Phycologia (2008) Volume 47 (2), 124–155
Published 12 March 2008
Morphological and molecular systematic study of Chondracanthus
(Gigartinaceae, Rhodophyta) from Pacific North America
JEFFERY R. HUGHEY1*
AND
MAX H. HOMMERSAND2
1
Division of Science and Mathematics, Hartnell College156 Homestead Ave., Salinas, CA 93950, USA
Department of Biology, Coker Hall, University of North CarolinaChapel Hill, NC 27599-3280, USA
2
J.R. HUGHEY AND M.H. HOMMERSAND. 2008. Morphological and molecular systematic study of Chondracanthus
(Gigartinaceae, Rhodophyta) from Pacific North America. Phycologia 47: 124–155. DOI: 10.2216/07-36.1
Species boundaries in the Gigartinaceae are poorly defined due to the high degree of phenotypic plasticity exhibited by
the thallus, with the result that many superfluous taxa have been described. To clarify the taxonomy of species of
Chondracanthus Kützing reported from the Gulf of California and Pacific coast of North America, morphological and
molecular phylogenetic studies were performed. Phylogenetic analyses of chloroplast and nuclear DNA yielded nearly
congruent hypotheses. DNA from type material was examined from select species to validate the correspondence
between modern and historically important collections. Monographic observations on species from Pacific North
America were included to clarify species boundaries. Analyses identified two species from the Gulf of California and
nine from the Pacific coast. The following statements are supported: (1) Gigartina serrata Gardner is independent of
Chondracanthus canaliculatus (Harvey) Guiry, and Chondracanthus serratus (Gardner) comb. nov. is being proposed. (2)
Thalli genetically close to C. canaliculatus but morphologically similar to G. serrata represent a new species of
Chondracanthus from Pacific Baja California, Mexico, Chondracanthus bajacalifornicus sp. nov. (3) Pinnate thalli
previously referred to C. canaliculatus but larger and closely related to C. canaliculatus and C. bajacalifornicus represent
a new species of Chondracanthus from southern California, Chondracanthus kjeldsenii sp. nov. (4) Gigartina californica J.
Agardh is conspecific with C. corymbiferus (Kützing) Guiry. (5) Gigartina boryi Setchell & Gardner is a heterotypic
synonym of C. harveyanus (Kützing) Guiry. (6) Chondracanthus spinosus (Kützing) Guiry is a polymorphic species that
includes G. armata J. Agardh, G. asperifolia J. Agardh, G. echinata Gardner, G. eatoniana J. Agardh, and G. farlowiana
J. Agardh. (7) Chondracanthus exasperatus (Harvey & Bailey) Hughey encompasses a range of forms of varying size,
margin shape, pigmentation, and thickness. (8) Gigartina acicularis sensu Dawson from the Gulf of California, C.
johnstonii (Dawson) Guiry, C. macdougalii (Dawson) Guiry, and G. pectinata Dawson are conspecific with C.
squarrulosus (Setchell & Gardner) Hughey, P. C. Silva & Hommersand. (9) Chondracanthus intermedius is tentatively
confirmed in the Gulf of California.
KEY WORDS: Chondracanthus, Gigartinaceae, Gulf of California, Pacific North America, Rhodophyta, species,
taxonomy, rbcL, ITS
INTRODUCTION
Chondracanthus Kützing (1843) is one of seven genera
currently recognized in the red algal family Gigartinaceae.
The genus contains approximately 18 species that are
distributed in New Zealand, Japan, Pacific North and
South America, and the North and South Atlantic Ocean
with a present center of distribution in the eastern North
Pacific Ocean (Hommersand et al. 1993). Thalli are soft to
firmly cartilaginous and variously branched to bladelike
and bear reproductive structures on ordinary branches,
pinnules, or spines, the latter for which the generic name
was proposed (Greek khondros, cartilage + acantha, spine).
Chondracanthus is currently restricted to Gigartinaceae
having auxiliary cells that form few gonimoblast initials
that are directed inwardly and surrounded by a compact
envelope divisible into inner vacuolated and outer cytoplasm-rich layers, with the gonimoblast filaments penetrating the inner layer and linking to the outer envelope by
secondary pit connections and with carposporangia borne
in short chains interspersed among the sterile gonimoblast
* Corresponding author (jhughey@hartnell.edu).
124
and envelope cells (Hommersand et al. 1993). Species are
distinguished based on thallus shape, size, color, and
intertidal position, although these characters show great
variability.
A tally of the species shows a marked discrepancy
between the number of taxa originally described and those
currently recognized. Nineteenth-century authors (especially J. Agardh, Harvey, & Kützing) described about 70
species that were assigned to Gigartina Stackhouse (1809)
or to the segregate genera established by Kützing, namely,
Chondracanthus, Chondroclonium Kützing (1845), Chondrodictyon Kützing (1849), Mastocarpus Kützing (1843), and
Sarcothalia Kützing (1849). Of the nearly 40 species
recognized by Kützing (1849), 6 were recorded from North
America, 1 placed in Chondroclonium, 2 in Gigartina, and 3
in Mastocarpus. These segregate genera were all referred to
Gigartina by J. Agardh (1851 [1851–1863]), who assigned 23
species to the genus. J. Agardh (1876) later increased the
number to 39, of which 7 came from the eastern north
Pacific. In his final revision of the genus, J. Agardh (1899)
recognized 69 species of which 19 were from the Pacific
coast of North America. Gardner (1927) and Setchell &
Gardner (1933) augmented the list, describing six new
species from the Pacific coast. In their final but preliminary
Hughey & Hommersand: Systematics of Chondracanthus
survey of Gigartina, Setchell & Gardner (1933) treated
Kützing’s segregate genera as subgenera and recognized 88
species worldwide, recording 3 from the Gulf of California
and 27 from the Pacific coast. Dawson (1944, 1946)
increased the number, describing 3 new species from to
the Gulf of California and 1 from the Pacific coast.
Consolidation of the numerous species attributed to the
Pacific coast of North America was initiated by Dawson
(1961) in his account of the Gigartinaceae of Pacific
Mexico. He recognized 17 species and reduced 8 previously
recognized species to synonymy. Gigartina binghamiae J.
Agardh (1899) was synonymized with G. corymbifera
(Kützing) J. Agardh (1876) [Mastocarpus corymbiferus
Kützing 1847] and G. boryi Setchell & Gardner (1933) with
G. harveyana (Kützing) Setchell & Gardner (1933) [M.
harveyanus Kützing 1847]. More important was his
perception that G. armata J. Agardh (1899), G. echinata
Gardner (1927), G. spinosa (Kützing) Harvey (1853) [M.
spinosus Kützing 1847], G. eatoniana J. Agardh (1899), and
G. asperifolia J. Agardh (1899) ’are variations of an
exceedingly polymorphic complex that defies specific
segregation’. This complex was treated as a single species,
G. spinosa, by Abbott (1972) and Abbott & Hollenberg
(1976). Plants from the Gulf of California that were
interpreted by Setchell & Gardner (1924) as G. chauvinii
were placed in synonymy with G. pectinata Dawson (1944)
by Dawson (1961). In the same monograph, Dawson (1961)
merged G. leptorhynchos forma caespitosa Dawson (1949)
with G. multidichotoma Dawson (1946). Abbott & Hollenberg (1976) further condensed the list of species from
California to 10, treating G. multidichotoma as synonymous
with G. leptorynchos J. Agardh (1885), G. serrata Gardner
(1927) as conspecific with G. canaliculata Harvey (1841),
and G. californica J. Agardh (1899) as conspecific with G.
exasperata Harvey & Bailey (1851). After observing
morphological variation in cultured G. exasperata and
studying reproductive development in Gigartinaceae, Kim
(1976) finalized the consolidation by merging G. exasperata,
G. spinosa, G. californica, G. harveyana, and G. corymbifera
under the name G. corymbifera.
Working with cultures, Polanshek & West (1977) showed
that certain populations of G. papillata (C. Agardh) J.
Agardh (1846) [Sphaerococcus papillatus C. Agardh 1821]
comprise sexual plants that alternate with a tetrasporangial
crust previously treated as an independent genus, Petrocelis.
Since most species of Gigartina (including the type species)
have isomorphic reproductive stages, those species with an
alternation of heteromorphic stages appeared to warrant
generic separation. Guiry & West (1983) showed that G.
stellata (Stackhouse) Batters (1902) [Fucus stellatus Stackhouse in Withering 1796] had a life history similar to that of
G. papillata. Because G. mamillosa (Goodenough & Woodward) J. Agardh (1851) [Fucus mamillosus Goodenough &
Woodward 1797], which was designated the type species of
Mastocarpus by Setchell & Gardner (1933), is a taxonomic
synonym of G. stellata, it follows that Mastocarpus was
available to accommodate species of Gigartina having
a heteromorphic alternation of generations. Accordingly,
Mastocarpus was reinstated by Guiry et al. (1984) and
assigned to its own family, the Petrocelidaceae, named for
Petrocelis, the tetrasporangial stage. Molecular studies by
125
Fredericq & Ramirez (1996) established that Mastocarpus
forms a well-supported clade within the Phyllophoraceae,
and the most recent treatment (Guiry & Guiry 2007) places
Mastocarpus in the Phyllophoraceae.
On the basis of reproductive morphology and an analysis
of rbcL gene sequences, Hommersand et al. (1993, 1994)
reorganized the genera within the Gigartinaceae. Among
the species remaining in the Gigartinaceae from the eastern
North Pacific, Hommersand et al. (1993) referred G. volans
(C. Agardh) J. Agardh (1846) [Sphaerococcus volans C.
Agardh 1821] and G. leptorynchos to Mazzaella G. Detoni
f. (1936). Only 5 species from the Pacific coast were retained
in Chondracanthus – C. canaliculatus (Harvey) Guiry in
Hommersand et al. (1993), C. corymbiferus (Kützing) Guiry
in Hommersand et al. (1993), C. harveyanus (Kützing)
Guiry in Hommersand et al. (1993), C. spinosus (Kützing)
Guiry in Hommersand et al. (1993), C. tepidus (Hollenberg)
Guiry in Hommersand et al. (1993) [G. tepida Hollenberg
1945] – and 2 from the Gulf of California – C. johnstonii
(Dawson) Guiry in Hommersand et al. (1993) [G. johnstonii
Dawson 1944] and C. macdougalii (Dawson) Guiry in
Hommersand et al. (1993) [G. macdougalii Dawson 1944].
Two names were reinstated, one from the Pacific coast, C.
exasperatus (Harvey & Bailey) Hughey in Hughey et al.
(1996), and the other from the Gulf of California, C.
pectinatus (Dawson) L. Aguilar & R. Aguilar (1997) [G.
pectinata Dawson 1944]. Chondracanthus pectinatus, however, was recently treated as a heterotypic synonym of C.
squarrulosus [Grateloupia squarrulosa Setchell & Gardner
1924] (Hughey et al. 2001). A summary of the nomenclatural history of species previously referred to as Gigartina
from the eastern North Pacific is provided in Table 1.
At present, four species are recognized from the Gulf of
California and six from the Pacific coast (Hommersand et
al. 1993, 1994, 1999). The purpose of this study is to
investigate the taxonomic revisions proposed for Chondracanthus by earlier (Kützing 1847, 1849; Harvey 1841, 1853;
J. Agardh 1899; Setchell & Gardner 1933) and later
(Dawson 1944, 1961; Abbott 1972; Abbott & Hollenberg
1976; Kim 1976; Hommersand et al. 1993, 1994, 1999)
workers. To address the taxonomy, the plastid rbcL gene
(large subunit of ribulose-1,5-biphosphate carboxylase/
oxygenase) and the Internal Transcribed Spacer (ITS)
regions one and two and the 5.8 S gene (nrDNA) were
analyzed. Where necessary, the ITS 1 region of the original
material was sequenced to confirm correspondence between
type and recent collections (Hughey et al. 2001). In
addition, a diagnosis of each species, lists of synonyms,
references to previous studies and illustrations, and details
of the morphological characters are included for species
from Pacific North America.
MATERIAL AND METHODS
DNA extraction, amplification, and sequencing
Specimens were silica gel (Fisher Scientific, USA) dried in
the field and then stored at 220uC until further processing.
Extractions followed Lee & Taylor (1990): 200 mg of silica
gel dried tissue were ground to a fine powder in liquid
126
Phycologia, Vol. 47 (2), 2008
Table 1. Nomenclatural summary of species previously treated as Gigartina from the Gulf of California and Pacific North America. C.,
Chondracanthus; G., Gigartina; Maz., Mazzaella; and R., Rhodoglossum; NA, not applicable
Setchell &
Gardner
1933
Dawson
1961
Abbott &
Hollenberg
1976
G. agardhii
G. armata
G. asperifolia
G. binghamiae
G. boryi
G. californica
G. canaliculata
G. corymbifera
G. cristata
G. dichotoma
G. eatoniana
G. echinata
G. exasperata
G. farlowiana
G. harveyana
G. jardinii
G. latissima
G. leptorynchos
G. mamillosa
G. obovata
G. papillata
G. serrata
G. sitchensis
G. spinosa
G. stellata
G. turneri
G. unalaschcensis
G. velifera
G. volans
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
G. armata
G. asperifolia
G. corymbifera
G. harveyana
G. californica
G. canaliculata
G. corymbifera
G. papillata
NA
G. armata
G. armata
NA
NA
G. harveyana
NA
NA
G. leptorynchos
NA
G. papillata
G. papillata
G. serrata
NA
G. spinosa
NA
NA
NA
NA
G. volans
G. intermedia
G. johnstonii
G. macdougalii
G. pectinata
G. multidichotoma
G. tepida
R. linguiforme
NA
NA
G. agardhii
G. spinosa
G. spinosa
G. corymbifera
G. harveyana
G. exasperata
G. canaliculata
G. corymbifera
G. papillata
G. papillata
G. spinosa
G. spinosa
G. exasperata
G. spinosa
G. harveyana
NA
NA
G. leptorynchos
G. papillata
NA
G. papillata
G. canaliculata
G. papillata
G. spinosa
NA
NA
NA
G. volans
G. volans
NA
NA
NA
NA
G. leptorynchos
G. tepida
G. volans
NA
NA
nitrogen using a mortar and pestle. The powder was
transferred to a 1.7-ml microcentrifuge tube (1/3 up the
conical) and then saturated with 400 ml of a 50 mmol TrisHCL (pH 7.2), 50 mmol EDTA, 3% SDS, 1% 2-mercaptoethanol buffer solution. Samples were vortexed for 5 s
and then incubated at 65uC for 1 h. Two hundred
microliters of 2.5 mol potassium acetate were added; tubes
were shaken and then incubated on ice for 20 min to
remove phycocolloids (Steane et al. 1991). Proteins and
DNA were extracted with 400 ml of phenol and chloroform
and then centrifuged for 35 min at 12,000 rpm. The
aqueous phase (300 ml) was removed and placed in a new
tube, where 10 ml of 3 mol NaOAc were added followed by
66% (200 ml) of 220uC isopropanol. Tubes were inverted 20
times, then stored at 220uC for 1 h. Samples were
centrifuged for 5 min to pellet the DNA, which was then
washed with 200 ml of 70% ethanol to remove salts. Excess
ethanol was removed by air-drying for 1 h. DNA was
resuspended with 100 ml of distilled water or TE (10 mmol
TrisNCl, 1 mmol EDTA, pH 8.0). A working solution of
10 : 1 (water : DNA) was prepared for the polymerase
chain reaction.
Kim
1976
Removed from family
G. corymbifera
G. corymbifera
G. corymbifera
G. corymbifera
G. corymbifera
G. canaliculata
G. corymbifera
removed from family
removed from family
G. corymbifera
G. corymbifera
G. corymbifera
G. corymbifera
G. corymbifera
removed from family
removed from family
G. leptorynchos
removed from family
removed from family
removed from family
NA
removed from family
G. corymbifera
removed from family
removed from family
removed from family
NA
G. volans
NA
NA
NA
NA
NA
G. tepida
NA
NA
NA
Hommersand
et al.
1993, 1994, 1999
NA
NA
NA
NA
NA
NA
C. canaliculatus
C. corymbiferus
NA
NA
NA
NA
C. exasperatus
NA
C. harveyanus
NA
NA
Maz. leptorynchos
NA
NA
NA
NA
NA
C. spinosus
NA
NA
NA
NA
Maz. volans
C. intermedius
C. johnstonii
C. macdougalii
NA
NA
C. tepidus
NA
NA
NA
Name resulting
from this study
NA
C. spinosus
C. spinosus
C. corymbiferus
C. harveyanus
C. corymbiferus
C. canaliculatus
C. corymbiferus
NA
NA
C. spinosus
C. spinosus
C. exasperatus
C. spinosus
C. harveyanus
NA
NA
NA
NA
NA
NA
C. serratus
NA
C. spinosus
NA
NA
NA
NA
NA
C. intermedius
C. squarrulosus
C. squarrulosus
C. squarrulosus
NA
C. tepidus
NA
C. bajacalifornicus
C. kjeldsenii
The methods for DNA extraction from herbarium
specimens followed Hughey et al. (2001, 2002). The
methods for amplification and sequencing followed Hughey
et al. (2001, 2002). The rbcL and ITS primers used in this
study were published previously (Hommersand et al. 1994;
Hughey et al. 2001).
Alignment and choice of outgroup
The boundaries of the ITS regions were determined from
published sequences (Goff et al. 1994; Van Oppen et al.
1995). Alignment of rbcL sequences was performed visually
using PAUP* 4.0.0b4, E Smithsonian Institution (Swofford
2000). The ITS 1, 2, and 5.8 S regions were preliminarily
aligned with the Clustal W 1.61 alignment program and
then optimized manually in PAUP. The following Clustal
parameters were used to generate the initial sequence
alignment: slow toggle alignment; Gonnet series substitution matrix; gap opening of 10.00, extension of 0.20, and
separation penalty of 8; delaying divergent sequences at
30%; and a transweight of 0.50.
Outgroup selection was based on the results inferred
from a parsimony analysis of the rbcL gene (Hommersand
Hughey & Hommersand: Systematics of Chondracanthus
127
et al. 1994, 1999). Chondracanthus acicularis was selected to
root the tree.
homogeneity tests (PHT) with 100 replicates. A probability
of 0.05 was taken as the threshold for significance.
Maximum-parsimony analysis
Skewness of the random tree-length distribution
In search of the tree with the fewest number of steps, two
types of parsimony analyses were performed. Type 1:
Searches were initiated with 1000 random sequence
additions and holding 100 trees at each step while using
the nearest-neighbor interchange (NNI) swapping algorithm. Trees found in these searches were used as starting
points for a second search using the tree-bisectionreconnection (TBR). The steepest descent option was in
effect for these searches. Type 2: Trees were obtained via
simple stepwise addition holding one tree at each step
during the addition sequence while swapping on best trees
only. NNI and TBR branch-swapping algorithms were
employed, and the steepest descent option was turned off.
For type 1 and 2 analyses, heuristic searches were carried
out treating parsimony-informative characters as unordered and with equal weight. Uninformative characters
were excluded from analyses, and gaps were treated as
missing. Branches were set to collapse if minimum branch
length was zero (‘amb-’). For both analyses, the MulTrees
and Collapse options were in effect. The consistency index
(CI) and retention index (RI) (Kluge & Farris 1969; Farris
1989) were calculated by excluding uninformative characters. Support for parsimonious trees was assessed by
calculating bootstrap proportion (BP) values (Felsenstein
1985) based on 1000 resamplings. Bootstrap searches were
executed using the settings described for type 2.
The shape of a tree-length distribution is an indication of
the presence or absence of phylogenetic signal in a data set
(Huelsenbeck 1991). When distributions are significantly
more skewed than expected from random data, the chances
are good that parsimony analysis will find the true
phylogeny (Hillis & Huelsenbeck 1992). The g1 statistic
(skewness test statistic) is used to measure skewness (Sokal
& Rohlf 1981). A perfectly symmetrical tree-length
distribution has a g1 that is equal to zero, whereas a leftskewed distribution has a negative g1. Data matrices with
phylogenetic signal produce tree-length distributions that
are strongly skewed to the left. The critical g1 value
depends on the number of characters and taxa. Assuming
25 or more operational taxonomic units and 10 or more
characters, a g1 greater than 20.10 allows for 95%
confidence that a particular data set has phylogenetic
signal (Hillis & Huelsenbeck 1992).
Maximum-likelihood analysis
To determine the appropriate substitution model, Modeltest 3.8 (Posada & Crandall 1998) was employed. Searches
were performed on rbcL and ITS data sets using the Akaike
Information Criterion among 56 potential best-fit models.
The rbcL model was determined as TrN + I + G (TamuraNei plus invariable sites plus gamma, where A-C 5 1.0, AG 5 3.4851, A-T 5 1.0, C-G 5 1.0, C-T 5 5.9082, G-T 5
1.0, proportion of invariable sites 5 0.7031, and gamma
distribution 5 1.3212) and the ITS model GTR + G
(general time reversible plus gamma, where A-C 5 1.6998,
A-G 5 1.7892, A-T 5 1.1042, C-G 5 0.7935, C-T 5
2.8780, G-T 5 1.0, proportion of invariable sites 5 0.0, and
gamma distribution 5 0.2689). All characters were included
in the analyses. Starting branch lengths were obtained using
the least-squares method with Jukes–Cantor distances.
Trees with approximate likelihoods of 5% or further from
the target score were rejected without additional iteration.
Starting trees were obtained via stepwise addition using asis
and holding one tree at each step during additions. The
TBR algorithm was selected for swapping.
Combined analysis
Parsimony search options followed those described previously for the type 2 maximum-parsimony analysis. Full
heuristic searches were performed with simple taxon
addition and NNI branch swapping. The level of incongruence between partitions was tested using partition
Phylogenetic species concepts
Two species concepts have been proposed (Baum &
Donoghue 1995). One is history based, where species are
defined by historical or phylogenetic relationships. The
other is character based, in which species are defined by the
possession of attributes or characters. For phylogram
interpretation, we feel a history-based approach, using the
rule of exclusivity to define species, fits best because trees
are meant to reflect true phylogenetic relationships and are
presented as evolutionary hypotheses. Exclusivity is a Hennig (1966) concept, restricted to members of a group that
are more closely related to each other than they are to those
outside their group. We adopt the use of a character-based
approach to identify type material. In this paper, type
material was correlated with sequences of the ITS 1 region
from modern materials. The ITS 1 is variable between
species but uniform within species in the Gigartinaceae
(Hughey et al. 2001, 2002). The ITS 1 region is an ideal
target because it is multicopy tandem repeat and is short in
size (139–156 base pairs [bp]). These two characteristics
improve the likelihood of successfully amplifying DNA
from older or formalin-fixed specimens, which characteristically contain fragmented DNA.
Anatomical examination
Material was preserved in 10% formalin/seawater and then
maintained in 5% formalin/seawater or mounted onto
herbarium paper. Algal fragments were hydrated in
seawater for 1–5 min, then frozen in a 1% gum arabic
solution on the stage of a freezing microtome. Sections were
made at widths of 10–30 mm and then stained for 2–10 min
with a solution of 0.125% aniline blue, 1% HCL, 20%
KaroH corn syrup, and 79% seawater. Sections were
destained with a 50% glycerine/50% seawater solution,
sorted, transferred onto a slide with 25 ml of Wynne’s stain,
and then covered with a 22 mm2 coverslip. Slides with
sections were allowed to set for 24 h, then photographed
128
Phycologia, Vol. 47 (2), 2008
Table 2. Specimens analyzed in this study. NA, not applicable.
Species and authority
Chondracanthus acicularis (Roth)
Fredericq
Chondracanthus bajacalifornicus
Hughey et Hommersand sp. nov.
C. bajacalifornicus Hughey et
Hommersand sp. nov.
C. bajacalifornicus Hughey et
Hommersand sp. nov.
Chondracanthus canaliculatus
(Harvey) Guiry
C. canaliculatus (Harvey) Guiry
C. canaliculatus (Harvey) Guiry
C. canaliculatus (Harvey) Guiry
Chondracanthus chamissoi
(C. Agardh) Kützing
Chondracanthus chapmanii (J.D.
Hooker et Harvey) Fredericq
Chondracanthus corymbiferus
(Kützing) Guiry
C. corymbiferus (Kützing) Guiry
C. corymbiferus (Kützing) Guiry
C. corymbiferus (Kützing) Guiry
C. corymbiferus (Kützing) Guiry
Chondracanthus exasperatus
(Harvey et Bailey) Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
C. exasperatus (Harvey et Bailey)
Hughey
Chondracanthus harveyanus
(Kützing) Guiry
C. harveyanus (Kützing) Guiry
C. harveyanus (Kützing) Guiry
Collection information
Île Verte, Roscoff, Brittany, France, J. Cabioch,
9.iii.1993
Punta San Tomás, Baja California, Mexico, M.H.
Hommersand, 2.vii.1996
San Miguel Beach, Baja California, Mexico, C.K.
Kjeldsen, 27.iii.1989, #8293
Punta Baja, Baja California, Mexico, J.R. Hughey,
3.vii.1996
Carmel Beach, Carmel, Monterey Co., California,
J.R. Hughey, 13.vii.1996
Pescadero Pt., Monterey, Monterey Co., California,
J.R. Hughey, 12.viii.1995
Pigeon Point, San Mateo Co., California, M.H.
Hommersand, 20.v.1992
S. end of La Jolla shores, San Diego Co., California,
J.R., P.A. & D.R. Hughey, 24.xii.1995
Lechagua, near Ancud, Chiloé, Chile, S. Fredericq
& M.E. Ramı́rez, 23.ii.1993
Island Bay, Wellington, New Zealand, W.A. Nelson,
23.v.1993
Santa Cruz, Santa Cruz Co., California, C.L.
Anderson, unknown date, lectotype, LD 23933
Indian Island, Kitsap Co., Washington, M.H.
Hommersand, 10.vi.1994
Nick’s Cove, Tomales Bay, Marin Co., California, J.R.
Hughey, 1995
Pacific Grove, Monterey Co., California, J.R. Hughey,
11.vii.1995
Pigeon Pt., San Mateo Co., California, M.H.
Hommersand, 21.xii.1992
opposite Fort Nisqually, Tacoma Co., Washington,
unknown coll., 1838–1842, lectotype, 94544
Carmel Pt., Carmel, Monterey Co., California, J.R.
Hughey, 3.xi.1994
drift, Bahia Colnett, Baja California, Mexico, J.R.
Hughey, 2.vii.1996
drift, beach at Almar Ave., Santa Cruz, Santa
Cruz Co., California#1, J.R. Hughey, 11.vii.1995
drift, beach at Almar Ave., Santa Cruz, Santa Cruz
Co., California#2, J.R. Hughey, 11.vii.1995
drift, Coronado Is., San Diego, San Diego Co.,
California, M.H. Hommersand, 23.vi.1972
drift, Leadbetter Beach, Santa Barbara, Santa Barbara
Co., California, J.R. Hughey, 27.v.1995
Marshall, Tomales Bay, Marin Co., California, J.R.
Hughey, 19.x.1994
Neah Bay, Clallam Co., Washington, M.H.
Hommersand, 6.vi.1994
Nick’s Cove, Tomales Bay, Marin Co., California,
J.R. Hughey, 21.ii.1994
Pacific Grove, Monterey Co., California, J.R.
Hughey, 22.viii.1994.
Punta Maria, Baja California, Mexico, J.R. Hughey,
4.xii.1996
Tacoma Narrows, Tacoma Co., Washington #1, J.R.
Hughey, 4.v.1997
Tacoma Narrows, Tacoma Co., Washington #2,
J.R., P.A. & D.R. Hughey, 4.v.1997
ramp, Crissie Field, Fort Pt., San Francisco Co.,
California, M.H. Hommersand, 23.vii.1992
resequenced – misidentified as C. spinosus in
Hommersand et al. 1994 (UO2943)
Horseshoe Cove, Bodega Head, Sonoma Co.,
California, J.R. Hughey, 30.xii.1994
Pacific Grove, Monterey Co., California, J.R.
Hughey, 11.vii.1995
S. end of Carmel Beach, Monterey Co., California, J.R.
Hughey & M. F. Perez, 27.xii.1998
GenBank accession
numbers
rbcL
ITS
U02938
DQ869161
DQ869093
DQ869119
DQ869091
DQ869118
DQ869092
DQ869120
DQ869087
DQ869086
DQ869123
NA
DQ869124
DQ869088
DQ869125
AF146193
DQ869165
U02940
DQ869162
NA
DQ869167
DQ869094
DQ869128
NA
DQ869129
NA
DQ869131
U02941
DQ869130
NA
DQ869168
NA
DQ869141
DQ869105
NA
NA
DQ869133
DQ869109
DQ869137
NA
DQ871031
DQ869108
DQ869135
DQ869114
DQ869132
DQ869107
DQ869136
DQ869111
DQ869134
DQ869113
DQ869142
DQ869110
DQ869138
AF146194
DQ869139
DQ869106
DQ869140
DQ869112
DQ869143
DQ869116
DQ869144
AF146195
DQ869146
DQ869115
DQ869145
Hughey & Hommersand: Systematics of Chondracanthus
129
Table 2. Continued
Species and authority
Chondracanthus intermedius
(Suringar) Hommersand
C. intermedius (Suringar)
Hommersand
Chondracanthus kjeldsenii Hughey
et Hommersand sp. nov.
C. kjeldsenii Hughey et
Hommersand sp. nov.
Chondracanthus serratus (Gardner)
Hughey et Hommersand comb.
nov.
C. serratus (Gardner) Hughey et
Hommersand comb. nov.
C. serratus (Gardner) Hughey et
Hommersand comb. nov.
Chondracanthus spinosus (Kützing)
Guiry
C. spinosus (Kützing) Guiry
Collection information
Tokawa, Choshi, Chiba Pref., Japan, coll M. Yoshizaki,
22.v.1993
Algodones Beach, Sonora, Mexico, J.R. Hughey,
26.ii.1998
North and West Cove, San Clemente Is., Los
Angeles Co., California, S. Murray, 22.ii.1997
Mission Bay Jetty, San Diego, San Diego Co.,
California, J.R., P.A. & D.R. Hughey, 17.iii.1999
Enseneda, Baja California, Mexico, N.L. Gardner,
vii.1924, isotype, cystocarpic 4958
Mission Bay Jetty, San Diego, San Diego Co.,
California, J.R., P.A. & D.R. Hughey, 17.iii.1999
S. end of beach, La Jolla, San Diego Co.,
California, J.R., P.A. & D.R. Hughey, 24.xii.1995
drift, Black’s Beach, La Jolla, San Diego Co.,
California#1, J.R., P.A. & D.R. Hughey, 16.xii.1995
drift, Leadbetter Beach, Santa Barbara, Santa Barbara
Co., California #1, J.R. Hughey, 27.v.1995
C. spinosus (Kützing) Guiry
drift, Leadbetter Beach, Santa Barbara, Santa Barbara
Co., California #2, J.R. Hughey, 27.v.1995
C. spinosus (Kützing) Guiry
N. reef, Punta Baja, Baja California, Mexico, J.R.
Hughey, 3.vi.1996
C. spinosus (Kützing) Guiry
Pacific Grove, Monterey Co., California, J.R. Hughey,
14.vii.1996
C. spinosus (Kützing) Guiry
S. end of beach, La Jolla, San Diego Co.,
California#2, J.R., P.A. & D.R. Hughey, 1.xii.1996
C. spinosus (Kützing) Guiry
Scout Base, San Clemente Is., Los Angeles Co.,
California, S. Murray, 24.vi.1997
Chondracanthus squarrulosus
Smith Island, Gulf of California, Mexico, I. M.
(Setchell et Gardner) Hughey, Silva,
Johnston, 28.vi.1921, holotype, Herb. Calif. Acad.
et Hommersand
Sci. CAS 1368
C. squarrulosus (Setchell et Gardner) Isla Angel de la Guarda, Gulf of California,
Hughey, Silva, et Hommersand
Mexico, I.M. Johnston, 1.vii.1921, holotype of
Grateloupia johnstonii S. et G., Herb. Calif. Acad. Sci.
CAS 1371
C. squarrulosus (Setchell et Gardner) Puerto Libertad, Sonora, Gulf of California,
Hughey, Silva, et Hommersand
Mexico, D.T. MacDougal, 4.v.1923, isotype
G. macdougalii, AHF 44
C. squarrulosus (Setchell et Gardner) Isla San Esteban, Gulf of California, Mexico,
Hughey, Silva, et Hommersand
E.Y. Dawson, 5.ii.1940, holotype G. johnstonii,
Dawson 436-40
C. squarrulosus (Setchell et Gardner) Isla Angel de la Guarda, Gulf of California,
Hughey, Silva, et Hommersand
Mexico, E.Y. Dawson, 27.i.1940, holotype of
Gigartina pectinata Dawson, LAM 500907
C. squarrulosus (Setchell et Gardner) Bahı́a de los Angeles, Gulf of California,
Hughey, Silva, et Hommersand
Mexico #1, L. Aguilar, 1996
C. squarrulosus (Setchell et Gardner) Bahı́a de los Angeles, Gulf of California,
Hughey, Silva, et Hommersand
Mexico #2, J.R. Hughey, 5.vii.1996
C. squarrulosus (Setchell et Gardner) Cholla Bay, Sonora, Mexico, J.R. Hughey, 25.ii.1998
Hughey, Silva, et Hommersand
C. squarrulosus (Setchell et Gardner) Cholla Bay, Sonora, Mexico, J.R. Hughey, 25.ii.1998
Hughey, Silva, et Hommersand
C. squarrulosus (Setchell et Gardner) Cabo Lobos, Puerto Libertad, Sonora, Mexico, J.R.
Hughey, Silva, et Hommersand
Hughey, 1.iii.1998
Chondracanthus teedei (Roth)
Île Verte, Roscoff, Brittany, France, J. Cabioch,
Kützing
5.iii.1993
Chondracanthus tenellus (Harvey)
Okinoshima, Tateyama Bay, Chiba Pref., Japan, M.
Hommersand
Yoshizaki, 18.vi.1993
Chondracanthus tepidus (Hollenberg) S. Mission Bay, San Diego, San Diego Co., California,
Guiry
P.A. & D.R. Hughey, 6.iii.1996
GenBank accession
numbers
rbcL
ITS
U02942
DQ869159
DQ869117
DQ869160
DQ869084
DQ869126
DQ869085
DQ869127
NA
DQ869166
DQ869090
DQ869121
DQ869089
DQ869122
NA
DQ869148
DQ869097
DQ869150
DQ869096
DQ869149
DQ869099
DQ869151
AF148519
DQ869152
DQ869095
DQ869147
DQ869098
DQ869153
NA
AF401056
NA
AF401057
NA
DQ869170
NA
DQ869169
NA
AF401058
DQ869101
DQ869157
DQ869100
AF401059
DQ869102
DQ869155
DQ869104
DQ869156
DQ869103
DQ869154
U03024
DQ869164
AF146197
DQ869163
AF146197
DQ869158
130
Phycologia, Vol. 47 (2), 2008
Fig. 1. One of 52 equally parsimonious trees resulting from the rbcL gene analysis of Chondracanthus (245 steps, CI 5 0.66, RI 5 0.91). This
tree was identical in topology to the maximum-likelihood tree. Parsimony bootstrap values based on 1000 replicates are shown on branches
supported by more than 50%.
with a Zeiss photomicroscope III, using T-Max 100-speed
film. Negatives were scanned with a Polaroid SprintScan 35
and then adjusted with Adobe Photoshop 5.0. Papillae were
photographed using a Wild Photomacroscop M8 and
branchlets using a Wild Photomacroscop M400 with TMax 100 film.
Anatomical illustrations of Chondracanthus exasperatus
are provided to demonstrate distinguishing cystocarp and
tetrasporangial characters from the group. The reproductive development of C. exasperatus is consistent with other
species of Chondracanthus (subgenus Chondracanthus; non
subgenus Eogigartina).
Hughey & Hommersand: Systematics of Chondracanthus
131
Fig. 2. One of 24 equally parsimonious trees resulting from the ITS 1, 2, and 5.8S analysis of Chondracanthus (419 steps, CI 5 0.73, RI 5
0.95). This tree was identical in topology to the maximum-likelihood tree. Parsimony bootstrap values based on 1000 replicates are shown
on branches supported by more than 50%.
RESULTS AND DISCUSSION
Nucleotide sequence data for the rbcL gene was determined
for 45 specimens (Table 2). The length of the rbcL region
analyzed was 1401 bp. The number of variable sites was
213, of which 128 (60%) were phylogenetically informative.
Base frequencies showed an A + T bias: A, 0.312; C, 0.163;
G, 0.206; T, 0.320. Maximum-likelihood and parsimony
analyses produced trees that were in topological agreement.
Both parsimony methods (types 1 and 2) yielded trees that
were identical in length (245 steps). Type 2 parsimony
analysis of the rbcL gene using TBR yielded 52 most
parsimonious trees, CI 5 0.66, RI 5 0.91 (Fig. 1). The rbcL
data set provided strong phylogenetic signal according to
the skewness of the random tree-length distribution (X̄ 5
912.6, g1 5 20.43) (Hillis & Huelsenbeck 1992).
Sequence data for the ITS 1, 2, and 5.8S regions was
generated from 49 specimens (Table 2). The length varied in
ITS 1 from 139–156 bp and in ITS 2 from 353–415 bp. The
5.8 S was consistently 151 bp for all material examined in
this study. The number of variable sites was 258, of which
217 (84%) were phylogenetically informative. Base frequencies showed an A + T bias: A, 0.285; C, 0.198; G, 0.230; T,
0.288. Maximum-likelihood and parsimony analyses produced trees that were in topological agreement. Both
parsimony methods yielded trees that were the same length
132
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
(419 steps). Type 2 parsimony analysis of ITS regions using
TBR yielded 24 most parsimonious trees, CI 5 0.73, RI 5
0.95 (Fig. 2). Strong phylogenetic signal was detected in the
ITS data (X̄ 5 2149.7, g1 5 20.41) (Hillis & Huelsenbeck
1992).
Analysis of the combined data matrix using 42 ingroup
taxa resulted in two trees of 853 steps, CI 5 0.70, RI 5
0.93. Simultaneous analysis generated trees similar in
topology to those produced from the individual ITS and
rbcL analyses (not shown). Bootstrap support was higher in
comparison to ITS trees but slightly lower compared to
rbcL trees. Significant incongruence between the two
partitions was observed (PHT 5 0.02).
Topological relationships between species were similar
among rbcL and ITS data sets, although statistical support
varied. A species assemblage consisting of C. exasperatus,
C. spinosus, C. squarrulosus, and C. teedei (Roth) Lamouroux (1813) [Ceramium teedei Roth 1806] was adequately
supported (BP rbcL, 83%; ITS, 66%). Chondracanthus
exasperatus (BP rbcL, 99%; ITS, 72%) and C. spinosus (BP
rbcL, 99%; ITS, 64%) received strong to poor support.
Together they showed strong to moderate support as a clade
(BP rbcL, 93%; ITS, 74%). These two species were well
separated from related C. squarrulosus (BP rbcL, 100%;
ITS, 86%) and C. teedei (BP rbcL, 80%; ITS, 70%).
Based on these data, four species were resolved: C.
exasperatus (Figs 4–22), C. spinosus (Figs 23–27), C.
squarrulosus (Figs 28–31), and C. teedei, all of which are
morphologically distinct and show exclusivity. Chondracanthus exasperatus and C. spinosus were the most closely
related species in this group. Pairwise sequence divergences
for these two taxa were low (rbcL, 0.7–0.8%; ITS, 1.0–
1.7%). Comparatively, C. exasperatus vs C. squarrulosus
(rbcL, 1.4–1.6%; ITS, 2.5–3.2%) and C. exasperatus vs C.
teedei (rbcL, 3.0–3.1%; ITS, 3.8–5.0%) showed approximately two to three times the genetic distance. Intraspecific
variation was very low to zero for all four species.
Specimens in this study labeled C. exasperatus included
thalli identifiable as G. californica sensu Smith (1944),
proliferous forms of G. exasperata (Abbott & Hollenberg
1976), and large, pink pigmented specimens collected south
of Point Conception, California, sometimes but erroneously
referred to as G. binghamiae. These data support the earlier
findings of Hughey (1995), who concluded based on
molecular evidence from restriction endonuclease patterns,
transplantation studies, and clinal variation that the
previously described phenotypes represent a single species,
C. exasperatus.
Intraspecific sequence divergence in C. exasperatus
ranged from 1–3 bp for the ITS 1 region for 15 collections
distributed from Washington to Baja California (Fig. 3a).
A sequence from the lectotype of G. exasperata (Fig. 4) was
identical to four specimens, one of each from Tacoma and
133
Neah Bay, Washington, and from Santa Cruz and Santa
Barbara, California. The type, however, differed by 1 bp
from three collections with identical sequences from
Tomales Bay (two specimens) and Santa Cruz (one
specimen), California; 2 bp from three identical collections
from San Diego, Punta Baja, and Punta Maria, Mexico;
2 bp from a collection from Monterey, California, that
differed from the previous specimens; and 3 bp from
identical collections from Tacoma, Washington, and San
Francisco and Monterey, California. A sequence obtained
from the lectotype of Gigartina californica was identical to
two modern collections of C. corymbiferus, one from
Washington and the other from San Mateo, California
(Fig. 3a). It differed from collections of C. corymbiferus
from Monterey, California, by 2 bp and an exceptionally
thin-bladed form of this species from Tomales Bay,
California, by 4 bp. In comparison, interspecific sequence
divergence between the lectotype of C. exasperatus and
specimens of C. corymbiferus was greater than 20 bp
(Fig. 3a). This indicates that the placement of J. Agardh’s
plant into synonymy with G. exasperata, as proposed by
Abbott & Hollenberg (1976), is incorrect. The lectotype of
G. californica (Fig. 32) is in morphological agreement with
that of C. corymbiferus (Figs 33–36).
Specimens representing a range of forms currently
assigned to the name C. spinosus were indistinguishable
with rbcL and ITS sequences. Our data show that Dawson
(1961) was accurate in his perception that these species
belong to a single complex, as proposed by Abbott (1972)
and Abbott & Hollenberg (1976). Chondracanthus spinosus
also includes an intended new combination of the
illegitimate name C. armatus Hughey in Hughey et al.
(1996). Based on this genetic analysis, C. spinosus and C.
exasperatus are very closely related species. Comparison of
the ITS 1 region showed that the majority of the specimens
of C. spinosus and C. exasperatus from the Monterey
Peninsula (type locality of C. spinosus) differed by 4 bp for
the ITS 1 region. The collections of C. exasperatus from
Mexico, however, differed by 2 bp from C. spinosus from
Monterey and by only 1 bp from five collections of C.
spinosus from southern California and Mexico. According
to the ’test of sympatry’ (Stebbins 1966), if two species
maintain their character under identical environmental
conditions, with no intergradation, they are distinct species.
Chondracanthus spinosus and C. exasperatus in Monterey,
Santa Barbara, and San Diego, California, pass the test of
sympatry. At present there is no evidence to suggest that
populations of these two species in California are conspecific, but populations from Pacific Mexico require further
investigation.
Recent analysis of type material of Grateloupia squarrulosa (Fig. 28) and Grateloupia johnstonii Setchell & Gardner
(1924) showed that they, along with Chondracanthus
r
Fig. 3. Alignments of ITS 1 sequences from Chondracanthus. Dots are identical to the uppermost line and dashes indicate gaps. (a)
Chondracanthus exasperatus, C. spinosus, and C. corymbiferus. (b) Chondracanthus squarrulosus, C. johnstonii, C. macdougalii, and G.
pectinata. (c) Chondracanthus bajacalifornicus, C. canaliculatus, C. kjeldsenii, and Gigartina serrata. Ch., Chondracanthus; Gig., Gigartina;
Gr., Grateloupia. Refer to Table 2 for collection data.
134
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
pectinatus, represent a single, highly polymorphic taxon
from the Gulf of California, C. squarrulosus (Hughey et al.
2001). Examination of herbarium specimens of Chondracanthus acicularis (from the Gulf of California), Chondracanthus johnstonii, and Chondracanthus macdougalii raised
the possibility that hey too may be environmentally induced
forms of C. squarrulosus. Sequences generated from isotype
material (Fig. 3b) of Gigartina johnstonii (Fig. 29), Gigartina pectinata (Fig. 30), and a recent collection of
a specimen identified as Chondracanthus acicularis from
the Gulf of California were identical and similar to the
isotype of Gigartina macdougalii (1 bp) (Fig. 31). Compared to the holotype of C. squarrulosus, G. johnstonii, and
G. pectinata both showed a 1 bp difference (Fig. 3b).
Compared to G. macdougalii, C. squarrulosus differed by
2 bp. In comparing type collections to their modern
counterparts, the following nucleotide differences were
observed: recently collected Chondracanthus johnstonii
differed from the type specimen of the species by 3 bp, G.
pectinata differed from its type by 1 bp, and G. macdougalii
differed from its type by 3 bp (Fig. 3b). Chondracanthus
squarrulosus seems to encompass a large number of
genetically similar but morphologically divergent forms of
a single species. Chondracanthus acicularis from the Gulf of
California differed by more than 20 bp from the Atlantic
specimen and thus can be excluded from the flora.
Chondracanthus tepidus (Fig. 37) and C. chamissoi (C.
Agardh) Kützing (1843) [Sphaerococcus chamissoi C.
Agardh 1820] received strong support (BP rbcL, 99%;
ITS, 99%). The position of these two taxa and the species
occupying the terminal portion of the clade (C. exasperatus,
C. spinosus, C. squarrulosus, and C. teedei) was not
statistically robust (BP rbcL, 58%; ITS, 70%). Pairwise
sequence divergences between these species were low (rbcL,
0.9%; ITS, 2.6%) but sufficiently different to continue
species recognition. Attempts to amplify the ITS 1 region of
C. tepidus identified by Dawson from the Gulf of California
failed. Further study of C. tepidus is needed to confirm its
occurrence in the Gulf of California as well as its apparently
strong relationship with C. chamissoi.
The remaining species from Pacific North America
formed a potentially natural assemblage in the rbcL
analysis but received no support (BP , 50%) and went
unresolved in the ITS analyses. This grouping consisted of
six weak to strongly supported species: C. corymbiferus (BP
rbcL, 100%; ITS, 100%) (Figs 32–36); C. harveyanus (BP
rbcL, 99%; ITS, 100%) (Figs 38–41); Chondracanthus
bajacalifornicus sp. nov. from San Diego, California, and
Baja California, Mexico (BP rbcL, 95%; ITS, 100%)
(Figs 42–50); Chondracanthus kjeldsenii sp. nov. from
135
southern California (BP rbcL, , 50%; ITS, , 50%)
(Figs 51–55); Chondracanthus serratus comb. nov. (BP
rbcL, 85%; ITS, 98%) (Figs 56–62); and C. canaliculatus
(BP rbcL, , 50%; ITS, , 50%) (Figs 63–66). Chondracanthus corymbiferus and C. harveyanus differed moderately
from each other (rbcL, 1.7%; ITS, 7.0–7.3%), from C.
canaliculatus (rbcL, 2.1–2.4%; ITS, 6.5–7.1%), from C.
serratus (rbcL, 2.1–2.4%; ITS, 4.8–5.5%), from C. bajacalifornicus (rbcL, 2.2–2.4%; ITS, 6.5–7.0%), and from C.
kjeldsenii (rbcL, 2.2–2.4%; ITS, 7.0–7.2%). A specimen from
the Monterey Peninsula with proliferous margins, identifiable as Gigartina boryi (south end of Carmel Beach), was
identical in sequence to C. harveyanus. Modern collections
of C. serratus differed slightly in sequence from C.
canaliculatus (rbcL, 0.4–0.5%; ITS, 1.7–2.2%), C. bajacalifornicus (rbcL, 0.6%; ITS, 1.4–1.7%), and C. kjeldsenii
(rbcL, 0.0–0.4%; ITS, 2.1–2.3%). Moreover, Chondracanthus canaliculatus differed less from C. bajacalifornicus
(rbcL, 0.3–0.4%; ITS, 1.5–1.8%) and C. kjeldsenii (rbcL,
0.1%; ITS, 1.1–1.2%), as did C. bajacalifornicus from C.
kjeldsenii (rbcL, 0–0.3%; ITS, 1.2–1.4%).
Isotype material of C. serratus was identical in sequence to two plants identifiable as Gigartina canaliculata
f. laxa Collins (1906) from San Diego (one from La
Jolla, the other from the Mission Bay Jetty) (Fig. 3c). The
isotype differed by 19 bp from a specimen referable to
C. canaliculatus from Monterey, California. The Monterey specimen was similar to collections of C. canaliculatus
from San Mateo, California (1 bp), and La Jolla (2 bp)
but differed by 8–9 bp from two nearly identical sequences
of C. kjeldsenii from the Mission Bay Jetty and San
Clemente Island, respectively. The latter specimens differed
by 22 bp from isotype material of C. serratus. Chondracanthus bajacalifornicus (Ensenada, Punta Baja, and San
Miguel, Mexico) differs in sequence by 19–20 bp from the
type of C. serratus. Chondracanthus bajacalifornicus is
closely related to C. canaliculatus from Monterey, showing
7–8 bp divergence. The two specimens of C. kjeldsenii
differed in ITS 1 sequence by 8 bp or more from C.
canaliculatus.
Thalli of C. bajacalifornicus, C. canaliculatus, C. kjeldsenii, and C. serratus were found growing intermixed on the
Mission Bay Jetty in San Diego, California, and were
distinguishable with no evidence of intergradation. Chondracanthus kjeldsenii, C. bajacalifornicus, and C. canaliculatus are smaller and form dense clumps, while C. serratus is
large and lax. These observations, as well as the molecular
evidence outlined previously, support the hypothesis that C.
serratus is distinct from other species of Chondracanthus
and warrants removal from C. canaliculatus.
r
Figs 4–8. Chondracanthus exasperatus.
Fig. 4. Lectotype of Gigartina exasperata Harvey & Bailey, TCD 94544.
Figs 5–7. NCU 583004-07.
Fig. 5. Surface view of hemispherical cystocarpic papillae.
Fig. 6. Surface view of cystocarpic papillae using substage illumination to show shape and size of cystocarps. Each papilla with 1, 2, or
3 cystocarps.
Fig. 7. Surface morphology of male papillae.
Fig. 8. Surface view of nipple-like tetrasporic papillae with halos around papillae indicating the location where tetrasporangia are formed
and released, NCU 583402-03.
136
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
The remaining four species occupied the most basal
position on the tree: Chondracanthus intermedius (Suringar)
Hommersand in Hommersand et al. (1993) [Gigartina
intermedia Suringar 1870], C. tenellus (Harvey) Hommersand in Hommersand et al. (1993) [non G. tenella Harvey
1860, see Masuda et al. (1995)], C. chapmanii (J.D. Hooker
& Harvey) Fredericq in Hommersand et al. (1994) [G.
chapmanii J.D. Hooker & Harvey 1855], and C. acicularis
(Roth) Fredericq in Hommersand et al. (1993) [Ceramium
aciculare Roth (1806)]. The latter two species were poorly
resolved from the ingroup in the ITS analysis (BP ITS C.
chapmanii, 56%; C. acicularis, 55%), whereas C. intermedius
and C. tenellus were well resolved from the ingroup (BP ITS,
100%). Analysis of rbcL sequences showed a paraphyletic
relationship for C. intermedius and C. tenellus (BP rbcL,
99%). Based on the rbcL analysis, all four of these taxa form
a species assemblage that is well separated from the ingroup
(BP rbcL, 99%). This separation, however, was not observed
in the ITS analysis (BP ITS, 56%). Chondracanthus
intermedius and C. tenellus differed moderately from each
other (rbcL, 2.8%; ITS, 1.8–2.2%) but substantially when
compared together to C. chapmanii (rbcL, 4.7–6.1%; ITS,
7.8–8.6%) and C. acicularis (rbcL, 5.3–6.3%; ITS, 8.0–8.6%).
Our data suggest that C. intermedius or an alga very similar
to this species occurs in the Gulf of California (Figs 67, 68).
Tentatively, we recognize C. intermedius from the flora but
feel that further collections are needed to confirm the record
of this species from the region.
Chondracanthus Kützing (1843, p. 399)
TYPE SPECIES: Chondracanthus chauvinii (Bory) Kützing
(1843, p. 399).
Thalli composed of one or more erect axes from a discoid
or crustose holdfast, the erect axes initially cylindrical and
either remaining cylindrical or becoming compressed or
flattened; axes repeatedly pinnately branched or foliaceous
and either simple or basally or marginally proliferous, often
bearing numerous vegetative or reproductive branchlets, or
sparsely to thickly covered by vegetative or reproductive
papillae. Growth multiaxial by means of apical and
marginal meristems and consisting of files of outwardly
directed branched cortical filaments overlying an internal
network of medullary filaments. Primary medullary filaments initially elongating longitudinally and connecting
laterally and basally by one- to several-celled secondary
filaments to form a loose meshwork composed of narrow to
broad cells that are often flattened in the plane of the blade.
Gametophytes dioecious or monoecious. Spermatangia
formed in superficial sori on fertile branchlets, pinnules or
137
papillae. Procarps initiated near apex on branchlets,
pinnules or papillae and consisting of a supporting cell
modified from an inner cortical cell that bears a 3-celled
carpogonial branch; supporting cell functioning as the
auxiliary cell; auxiliary cell forming few protrusions and
gonimoblast initials from the inner side, surrounded by
a compact envelope often divisible into inner vacuolate and
outer cytoplasm-rich layers; gonimoblast filaments penetrating inner layer of envelope and linking to envelope cells
by secondary pit connections late in cystocarp development; carposporangia borne in short chains interspersed
among sterile gonimoblast filaments and enlarged envelope
cells; terminal tubular gonimoblast cells fusing with cells of
outer envelope; pericarp and ostiole sometimes present,
formed early in cystocarp development by resumed growth
of cortical filaments.
Tetrasporangial sori small to large, sometimes nemathecial, localized in inner cortex; tetrasporangia in simple or
branched chains, transformed from cells in primary cortical
filaments; secondary tetrasporangial filaments absent;
tetraspores released by gelatinous extrusion through pores
in outer wall.
Chondracanthus exasperatus (Harvey & Bailey)
Hughey in Hughey et al. (1996, p. 23)
Figs 4–22
BASIONYM: Gigartina exasperata Harvey & Bailey (1851, p. 371).
(LECTOTYPE: Fig. 4. A cystocarpic specimen in Herb. Harvey
No. 94544!, among a collection obtained by the United States
Exploring Expedition between 1838 and 1842, from opposite
Fort Nisqually, Puget Sound, Washington.)
Gigartina radula f. exasperata (Harvey
& Bailey) Setchell & Gardner (1903, p. 303).
HOMOTYPIC SYNONYM:
Bailey & Harvey (1862, p. 162, pl. 5, as
Gigartina exasperata); Olsen (1899, pp. 154–168, pl. XIII,
figs 1–13; pl. XIV, figs 14–24, as G. exasperata); Humphrey
(1901, pp. 601–607, pl. XLII, figs 1–15, as G. exasperata); Smith
(1944, p. 280, pl. 67, fig. 1, as G. californica); Dawson (1961, p.
265, pl. 50, fig. 1, after Smith); Abbott & Hollenberg (1976, p.
521, fig. 467, left, as G. exasperata; right, after Smith, as G.
californica).
ILLUSTRATIONS:
HABITAT:
Low intertidal, exposed rocky headlands to sheltered
localities.
DISTRIBUTION:
Ocean Cape, Yakutat Bay, Alaska (Lindstrom
1977, p. 107); Bank’s I., British Columbia (A. Menzies, ˜ 1787,
BM); Juan de Fuca Strait, Port Renfrew, Victoria, Cape Lazo,
British Columbia to Whidbey I., Channel Rocks, and Neah Bay
Wash. (Scagel 1957, p. 185); Puget Sound, Wash. (Thom et al.
1976, p. 272); Coos Bay, Cape Arago, Brookings, Oregon (Doty
1947, p. 181); Tomales Bay, Marin Co., Calif. (Hughey 1995, p.
48); San Francisco Bay, Calif. (Silva 1979, p. 326); Monterey
r
Figs 9–16. Cystocarpic development of Chondracanthus exasperatus, NCU 583004-07.
Fig. 9. Section through young cystocarp showing auxiliary cell, gonimoblasts, and developing envelope.
Fig. 10. Section through cystocarp showing inner gonimoblast filaments (broad arrow) and a dense envelope (narrow arrow).
Fig. 11. Section through cystocarp showing a compact envelope around the developing carposporophyte.
Fig. 12. Section showing the anatomy of the cells of the cortical region, medulla, and envelope.
Fig. 13. Close-up of tubular gonimoblast filaments linking to envelope cells that are surrounding the cystocarp in Fig. 12.
Fig. 14. Section through mature cystocarp showing well-defined ostiole and dense envelope.
Fig. 15. Section through an ostiole.
Fig. 16. Section through a papilla showing two fused cystocarps.
138
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
Peninsula, Calif. (Smith 1944, p. 280); Santa Barbara, Calif.
(Dawson 1959, p. 189); Punta Descanso, Punta Cabras, Punta
Baja, Punta Maria, Baja Calif. (Dawson 1961, p. 265).
Alaska: Cape Suspiro, W. side,
20 July 1978, SCL 3249, NCU 582979, tetrasporic; Canada: Ross
Islets, Vancouver I., 4 June 1985, NCU 582980-83, cystocarpic
and male; Washington: Friday Harbor, San Juan I. Co., 23 July
1993, NCU 582984, cystocarpic; Whidbey I., Island Co., 26
August 1969, NCU 582985, tetrasporic; Tacoma Narrows,
Tacoma Co., 28 May 1998, NCU 582986-95, cystocarpic, male,
tetrasporic; California: Stillwater Cove, Sonoma Co., 12 August
1998, NCU 582996, cystocarpic; Tomales Bay, Marin. Co., 19
October 1994, NCU 582997-98, sterile and cystocarpic; Duxbury
Reef, Marin Co., 22 February 1994, NCU 582999-3003,
cystocarpic, male, and tetrasporic; Crissie Field, San Francisco
Bay, San Francisco Co., 23 December 1992, NCU 583004-07,
cystocarpic, male, and tetrasporic; Beach at Almar Ave., Santa
Cruz, Santa Cruz Co., 19 October 1994, NCU 583008,
tetrasporic; 11 July 1995, NCU 583402-03, tetrasporic; Pacific
Grove, Monterey Co., 21 August 1994, NCU 583009, tetrasporic;
Mission Point, Monterey Co., 17 July 1974, NCU 583010-11,
cystocarpic; 19 August 1977, NCU 583012-13, tetrasporic;
Cambria, San Luis Obispo Co., 10 July 1996, NCU 583014-15,
tetrasporic; Hendry’s Beach, Santa Barbara Co., 16 May 1941,
E.Y.D. 873, NCU 583016, tetrasporic; La Jolla, San Diego Co.,
18 December 1945, M.H. 1261, NCU 583017, tetrasporic;
Coronado Hotel, Coronado, San Diego Co., 22 August 1971,
NCU 583018-20, cystocarpic and tetrasporic; Baja California:
Punta Piedras, La Misión, Baja California, 4–5 August 1968,
NCU 583021-22, cystocarpic and tetrasporic; Punta Descanso,
Baja California, 28 January 1968, NCU 583023-24, cystocarpic;
Santa Marta, Baja California, 30 July 1969, NCU 583025-26, male
and tetrasporic; Punta Banda, Baja California, 2 July 1969, NCU
583027-30, cystocarpic and tetrasporic; Punta Santo Tomás, Baja
California, 2 July 1996, NCU 583031-32, cystocarpic, male,
tetrasporic; Bahı́a Colnett, Baja California, 2 July 1996, NCU
583033-38, cystocarpic, male, tetrasporic; Punta Marı́a, Baja
California, 4 July 1996, NCU 583039-41, sterile; 10 miles S. of
Punta Eugenia, Baja California, 12 June 1972, NCU 583042-43,
cystocarpic and male.
REPRESENTATIVE SPECIMENS:
Thalli 20–70 cm tall, fleshy or crisp, yellowish-green to brownish-red in sheltered habitats, brick
red (north of Point Conception and in Baja California) or
pink (south of Point Conception to the Mexican border) on
exposed coasts, consisting of one to several blades from
a discoid holdfast up to 1 cm broad (Fig. 4); blades 6–
20 cm wide, 0.2–3 mm thick, simple or forked, lanceolate to
long-elliptical and tapered to a blunt or acuminate tip, the
margins entire or dentate or sometimes bearing bladelets;
stipitate, the stipe usually 2–3 cm long bearing lateral
bladelets and expanding to a short, fleshy and flattened
cuneate base; surface and margins of blades, except the base
covered with closely to widely spaced, spinose outgrowths;
cortex 5–7 cell layers thick; medullary cells variable in size
and shape, 1.5–24 mm in width. Spermatangial sori
superficial, indefinite on slender, elongate papillae with
thin attenuating tips (Fig. 7). Gonimoblast forming a comDESCRIPTION:
139
pact group of cells around the auxiliary cell (Fig. 9) with
cortical and medullary cells producing short-celled filaments circling the gonimoblasts (Fig. 10); later in development, a well-defined envelope composed of short and
dense filaments forms to surround the carposporophyte
(Figs 11, 13). Cystocarps 0.8–1.5 mm in diameter, hemispherical, frequently fusing to form a single, compound
cystocarp (Fig. 16), located in papillae that are sometimes
ornamented with spines, 1–3 per papilla (Figs 5, 6).
Carpospores subspherical, 12–18 mm in diameter, at
maturity released through an ostiole (Figs 14, 15). Tetrasporangial sori 0.2–1 mm in diameter (Fig. 20), developing
at the junction between the emerging papilla and the blade
(Fig. 17). Tetrasporangia 34–42 mm in diameter, transforming from primary cortical filaments in branched chains 9–12
cells long (Figs 17–21). As the papilla grows, the new
primary cortical filaments are transformed into tetrasporangial chains (Figs 18–21), sometimes forming 2–3 hemispherical rings of sori on the nipple-like papillae (Fig. 8). At
maturity tetraspores are released through cracks in the
cortical wall, leaving behind an empty cavity (Fig. 22).
Chondracanthus spinosus (Kützing) Guiry in
Hommersand et al. (1993, p. 115)
Figs 23–27
BASIONYM: Mastocarpus spinosus Kützing (1847, p. 24). (TYPE:
Fig. 23. A collection by Dr. T. Coulter between 1831 and 1833
from Monterey, Monterey Co., California, in Leiden, L941, 27
143!. The type collection consists of five cystocarpic specimens.)
HOMOTYPIC SYNONYM:
Gigartina spinosa (Kützing) Harvey
(1853, p. 177).
HETEROTYPIC SYNONYMS:
Chondracanthus armatus (J. Agardh) Hughey in Hughey et al.
(1996, p. 23); Gigartina armata J. Agardh (1899, p. 15). (TYPE: A
collection from San Diego, California by Dr. E. Palmer in Herb.
Agardh 23714.)
Gigartina asperifolia J. Agardh (1899, p. 15). (LECTOTYPE: A
tetrasporangial collection from Santa Barbara made by Mrs.
R.F. Bingham in Herb. Agardh 23716.)
Gigartina eatoniana J. Agardh (1899, p. 15). (LECTOTYPE: Two
specimens in Herb. Agardh, No. 23593, one is cystocarpic, sent
by Daniel C. Eaton, locality unknown.)
Gigartina echinata N.L. Gardner (1927, p. 335). (LECTOTYPE: A
specimen collected by M.B. Nichols from Santa Catalina Island,
California at the University of California in Berkeley [UC
93842].)
Gigartina farlowiana J. Agardh (1899, p. 15). (LECTOTYPE: A
specimen of unknown provenance in Herb. Agardh 23717,
designated by Setchell & Gardner [1933, p. 268, pl. 47, fig. 1].)
Gigartina ornithorynchos J. Agardh (1849, p. 86). (LECTOTYPE:
The upper right frond on Agardh 23708, lectotypified by Paul C.
Silva.)
r
Figs 17–22. Tetrasporic development of Chondracanthus exasperatus, NCU 583004-07.
Fig. 17. Section through fertile papilla showing tetrasporangial sori in various stages in development with tetrasporangia in
branched chains.
Fig. 18. Section showing young tetrasporangia in branched chains arising from primary cortical filaments.
Fig. 19. Section through papilla showing young chains adjacent to an excised tetrasporangial cavity.
Fig. 20. Mature tetrasporangial sorus.
Fig. 21. Close-up of Fig. 20.
Fig. 22. Section through the base of a papilla, showing empty sorus.
140
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
Kützing (1867, p. 17, pl. 47 a–c, as Mastocarpus spinosus); Harvey (1853, p. 177, pl. 28, fig. B, as Gigartina
spinosa); Gardner (1927, p. 335, pl. 63, 64, as G. echinata);
Setchell & Gardner (1933, p. 270, pl. 50, as G. asperifolia);
Setchell & Gardner (1933, p. 268, pl. 47, fig. 1, as G. farlowiana);
Setchell & Gardner (1933, p. 271, pl. 51, as G. eatoniana); Smith
(1944, p. 280, pl. 68, fig. 2, as G. spinosa); Dawson (1961, p. 262,
pl. 51, as G. armata var. armata); Dawson (1961, p. 264, pl. 52, as
G. armata var. echinata); Dawson (1961, p. 264, pl. 53, as G.
asperifolia); Dawson (1961, p. 274, pl. 63, as G. spinosa); Abbott
& Hollenberg (1976, p. 525, fig. 471, as G. spinosa).
ILLUSTRATIONS:
HABITAT: Exposed or moderately exposed localities on head
lands, mid-low intertidal.
DISTRIBUTION: Fort Mason, San Francisco Bay, Calif. (Silva
1979, p. 326); Monterey Peninsula, Calif. (Smith 1944, p. 280);
San Luis Obispo Co., Calif. (Sparling 1977, p. 69); Santa Barbara
and Southern Calif. (Dawson 1959, pp. 187, 189); Channel Is.,
Calif. (Murray 1974, p. 47); La Jolla, Calif. (Dawson 1945, p. 53);
Punta Descanso, Cabo Colonet, Punta Baja, to Isla San Martin,
Baja Calif. (Dawson 1961, p. 262).
REPRESENTATIVE SPECIMENS: California: Pacific Grove, Mon
terey Co., 22 August 1994, NCU 583044-48, cystocarpic, male, and
tetrasporic; 23 April 1995, NCU 583404-05, cystocarpic and
tetrasporic; Hendry’s Beach, Santa Barbara Co., 16 May 1941,
NCU 583049, male; Goleta Beach, Santa Barbara Co., 24 August
1977, NCU 583050-53, cystocarpic and tetrasporic; Carpenteria,
Santa Barbara Co., 20 July 1966, NCU 583054-55, cystocarpic and
tetrasporic; 27 May 1995, NCU 583056-59, cystocarpic and
tetrasporic; Scorpion Anchor, Santa Cruz I., Los Angeles Co.,
12 July 1969, NCU 583060-62, cystocarpic and male; Santa
Catalina I., Los Angeles Co., 9–10 August 1969, NCU 583063,
cystocarpic and tetrasporic; White’s Pt., Los Angeles Co., 27
December 1940, E.Y.D. 801A, NCU 583064, cystocarpic; Corona
Del Mar, Orange Co., 28 December 1940, E.Y.D. 801, NCU
583065-66, cystocarpic and sterile; Solano Beach, San Diego Co.,
April 1951, NCU 583067, tetrasporic; La Jolla, San Diego Co., 16
June 1945, M.H. 917-18, NCU 583068-69, cystocarpic and male;
La Jolla, June 1968, NCU 583070-71, male; 29 July 1969, NCU
583072, cystocarpic; Point Loma, San Diego Co., 20 June 1969,
NCU 583073-77, cystocarpic and tetrasporic; 15 September 1969,
NCU 583078, cystocarpic; Hotel Del Coronado, Coronado, San
Diego Co., 2 December 1944, M.H. 418, NCU 583079,
cystocarpic; 16 December 1945, M.H. 1182, NCU 583080-81,
cystocarpic; Baja California: Santa Marta, 28 January 1968, NCU
583082, male; 13 June 1968, NCU 583083, cystocarpic; Punta
Descanso, 8 April 1945, M.H. 861A, NCU 583084, cystocarpic; 28
January 1968, NCU 583085-86, cystocarpic, male, and tetrasporic;
Punta Cabras, 25 October 1969, NCU 583087-90, cystocarpic and
tetrasporic; Isla Todos Santos, 3 July 1969, NCU 583091,
tetrasporic; Cabo Colnett, 13 July 1968, NCU 583092-94,
cystocarpic and tetrasporic; Bahı́a Colnett, 2 July 1996, NCU
583095-96, cystocarpic and tetrasporic; Punta Baja, 12 July 1968,
NCU 583097-99, cystocarpic; 21 June 1974, NCU 583100,
cystocarpic and tetrasporic; 3 July 1996, NCU 583101-04,
cystocarpic, male, and tetrasporic.
DESCRIPTION: Thalli 25–60 cm high, coarse and thick,
greenish-red to dull red or black, consisting of several
blades from a discoid holdfast (Fig. 23); blades highly
141
variable, 1–12 cm wide, pinnate, distichous, to ligulate or
lanceolate in shape, arising from a short, cylindrical stipe
and narrowly expanding into an apophysis 7–10 cm long,
the stipe and smooth apophysis once or twice forked, the
blade with few to many irregular pinnate branches of
variable thickness; cortex 5–7 cell layers thick; medullary
cells variable in size and shape, 1.5–20 mm diameter.
Cystocarps 1.0–1.4 mm in diameter on surface and
marginal papillae, terminal on a pedicel or basal on an
elongate cylindrical papilla (Fig. 24); carpospores subspherical, 13–18 mm in diameter. Spermatangial sori superficial,
indefinite on thin simple papillae with acute tips (Fig. 25).
Tetrasporangial sori 210–320 mm in diameter, forming
ellipsoidal rings at the bases of papillae (Fig. 26); tetrasporangia 39–50 mm diameter, in chains 8–10 cells long.
Chondracanthus squarrulosus (Setchell & Gardner)
Hughey, Silva, & Hommersand (2001, p. 1105)
Figs 28–31
BASIONYM: Grateloupia squarrulosa Setchell & Gardner (1924, p.
780). (TYPE: Fig. 28. A collection by Ivan M. Johnston on 28
June 1921, from drift, Smith Island, Gulf of California, Mexico.
Housed in UC under CAS 1368!, isotypes are UC 221076!, UC
483280! The type consists of a single large, sterile specimen.)
HETEROTYPIC SYNONYMS:
Grateloupia johnstonii Setchell & Gardner (1924, p. 782). (TYPE:
A collection by Ivan M. Johnson [No. 88] made at Isla Angel de
la Guarda, Gulf of California, Mexico. CAS 1371 housed in UC.
The specimen is sterile.)
Chondracanthus johnstonii (Dawson) Guiry in Hommersand
et al. (1993, p. 115); Gigartina johnstonii (Setchell & Gardner)
Dawson (1944, p. 302). (TYPE: Fig. 29. Dawson 436, lower
intertidal rocks, San Esteban Island, Gulf of California, Mexico
[Herb. AHF no. 42].)
Chondracanthus macdougalii (Dawson) Guiry in Hommersand
et al. (1993, p. 115); Gigartina macdougalii Dawson (1944, p.
303). (TYPE: A collection by MacDougal from Puerto Libertad,
Sonora, 4 May 1923, housed in UC.)
Chondracanthus pectinatus (Dawson) L. & R. Aguilar (1997, p.
157); Gigartina pectinata Dawson (1944, p. 302). (TYPE: Dawson
239, cast ashore, north shore beach at Puerto Refugio, 27
January 1940, Herb. AHF no. 43.)
Setchell & Gardner (1924, p. 780, pls. 81, 82, as
Grateloupia squarrulosa; p. 782, pl. 84, as Grateloupia johnstonii;
p. 744, pls. 46b, 70, as Gigartina chauvinii; Dawson (1944, p. 302,
pl. 64, fig. 1); Dawson (1961, p. 273, pl. 61, fig. 1, as Gigartina
pectinata); Dawson (1944, p. 303, pl. 64, fig. 2); Dawson (1961, p.
271, pl. 58, fig. 2, as Gigartina macdougalii); West & Guiry (1982,
pp. 205–211, figs 1–24, as Gigartina johnstonii); L. Aguilar & R.
Aguilar (1997, p. 155–161, figs 1–7, as Chondracanthus pectinatus).
ILLUSTRATIONS:
HABITAT: Saxicolous and epizoic (on shells) in the mid and low
intertidal, sometimes detached and free-floating.
r
Figs 23–27. Chondracanthus spinosus.
Fig. 23. Lectotype of Mastocarpus spinosus Kützing, L 941, 27 143.
Figs 24, 26, 27. NCU 583404-05.
Fig. 24. Surface view showing robust, branched, and stalked cystocarpic papillae.
Fig. 25. Surface view of male papillae, NCU 583044-48.
Fig. 26. Surface view of young, elongated tetrasporic papillae with sori encircling the bases.
Fig. 27. Surface view of robust, elongated, older tetrasporic papillae with fewer sori and irregularly surfaced bases indicating the location
where tetrasporangia were released.
142
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
Puerto Libertad, Isla Patos, Isla Tiburón, Isla
San Esteban, Isla Ángel de la Guarda, Bahı́a de los Angeles,
Bahı́a Bocochibampo, Gulf of California, Mexico (Dawson
1961).
DISTRIBUTION:
143
Gigartina californica J. Agardh (1899, p. 39). (TYPE: Fig. 32. A
specimen collected by Dr. C.L. Anderson from Santa Cruz, Santa
Cruz County, California, in Herb. Agardh No. 23933.)
Kützing (1867, pl. 46, figs. a, b, as Mastocarpus
corymbiferus); Setchell & Gardner (1933, p. 275, pls. 53, 54, as
Gigartina corymbifera); Setchell & Gardner (1933, p. 272, pl. 52,
as G. californica); Setchell & Gardner (1933, p. 277, pl. 55, as G.
binghamiae); Smith (1944, p. 281, pl. 66, as G. corymbifera);
Dawson (1961, p. 267, pl. 55, as G. corymbifera); Dawson et al.
(1960, p. 60, pl. 30, as G. binghamiae); Abbott & Hollenberg
(1976, p. 518, fig. 466, as G. corymbifera).
ILLUSTRATIONS:
Gulf of California: Cholla Bay,
Puerto Peñasco, 6 April 1966, E.Y.D. 27263, NCU 583105, male;
18 March 1972, NCU 583106-12, cystocarpic, male, and
tetrasporic; 25 February 1998, NCU 583113-18, cystocarpic,
male, and tetrasporic; Puerto Libertad, 16 March 1972, NCU
583119-20, cystocarpic and tetrasporic; Bahı́a San Luis Gonzaga,
19 May 1972, NCU 583121, sterile; Cabo Tepoca, 14 March
1972, NCU 583122-24, cystocarpic and tetrasporic; Isla Smith, 28
June 1968, NCU 583125, tetrasporic; 29 June 1968, NCU
583126-28, tetrasporic; Punta la Gringa, Bahı́a de los Angeles, 22
May 1972, NCU 583129-39, tetrasporic and sterile; Isla la
Ventana, Bahı́a de Los Angeles, 28 June 1968, NCU 583140-41,
sterile; Algodones Beach, Guaymas, 12–13 March 1972, NCU
583142-43, cystocarpic and sterile.
REPRESENTATIVE SPECIMENS:
DESCRIPTION: Thalli 12–40 cm tall (larger in free-floating
forms), cartilaginous, greenish- to reddish-brown, consisting of one or more branched ligulate or abundantly
branched narrow blades from a holdfast of entangled
stolons around a small discoid holdfast (Figs 28–31); blades
highly variable, narrowly cuneate at the base, irregularly
pinnately to multifariously branched, the principal blade
parts 3–12 mm broad, acuminate at the apices, with spinose
outgrowths on blade surfaces and margins, some forms
with a distinct marginal zone free of spines, variable in
thickness; cortex 4–6 cell layers thick, medullary cells
variable in size and shape, sometimes vacuolate, 4–30 mm in
diameter. Cystocarps 500–720 mm diameter, globose, superficial and on marginal or superficial outgrowths or
spines; carpospores subspherical, 13–17 mm in diameter.
Spermatangia in small sori scattered over the surface of the
blade. Tetrasporangial sori 300–400 mm in diameter,
embedded in masses at the base of marginal and superficial
spinose outgrowths; tetrasporangia 32–39 mm in diameter,
in chains 4–6 cells long.
Chondracanthus corymbiferus (Kützing) Guiry in
Hommersand et al. (1993, p. 115)
Figs 32–36
BASIONYM: Mastocarpus corymbiferus Kützing (1847, p. 24).
(TYPE: Fig. 33. A collection by Dr. T. Coulter, 1831–1833, from
the Monterey Peninsula, Monterey County, California, in
Leiden, L941, 27 135! The type consists of two specimens, one
cystocarpic and the other an immature female thallus.)
HOMOTYPIC SYNONYM:
Gigartina corymbifera (Kützing) J.
Agardh (1876, p. 202).
HETEROTYPIC SYNONYMS:
Gigartina binghamiae J. Agardh (1899, p. 33). (TYPE: A collection
by Mrs. R.F. Bingham from Santa Barbara, Santa Barbara
County, California, in Herb. Agardh No. 23895. The type
contains two specimens, one cystocarpic and one a cluster of
basally attached specimens.)
HABITAT:
Exposed and sheltered habitats in the low intertidal.
DISTRIBUTION: Bamfield, Vancouver I., British Columbia (Scagel 1973, p. 138); throughout Oregon (Hansen 1997, p. 192);
Tomales Bay, Marin Co., Calif. (Hughey 1995, p. 48); Monterey
Peninsula, Calif. (Smith 1944, p. 281); San Luis Obispo Co.,
Calif. (Sparling 1977, p. 68); Punta Descanso, Punta Cabras, San
Quintin Peninsula, Baja Calif. (Dawson 1961, p. 267).
Canada: Ross Islets, Vancouver
I., 4 June 1985, NCU 583144, sterile; Tofino, Esowista Peninsula,
Vancouver I., 9 July 1980, NCU 583145, sterile; Washington:
Indian I., Puget Sound, 10 June 1994, NCU 583146-49,
cystocarpic, male, and tetrasporic; California: Horseshoe Cove,
Bodega Head, Sonoma Co., 20 June 1966, NCU 583150, sterile;
Davenport Landing, Santa Cruz Co., 9 August 1979, NCU
583151-55, cystocarpic; Pacific Grove, Monterey Co., 22 August
1994, NCU 583156, cystocarpic; 23 April 1995, NCU 583407-08,
cystocarpic and male; Islay, San Luis Obispo Co., 19 July 1966,
NCU 583157, cystocarpic; Pebble Beach, Monterey Co., 20 July
1974, NCU 583158, young tetrasporangial; Scorpion Anchor,
Santa Cruz I., Los Angeles Co., 12 August 1969, NCU 583159-61,
tetrasporic; Lady’s Cove, Santa Cruz I., 16 August 1969, NCU
583162-64, sterile; Solano Beach, San Diego Co., April 1951, NCU
583165-66, 66A, cystocarpic; Baja California: Punta Piedras, La
Misión, August 1969, NCU 583167, cystocarpic; 1 mile S. of Punta
Cabras, 25 October 1969, NCU 583168, cystocarpic; Isla San
Martin, 12 June 1969, NCU 583169, male, tetrasporic, and sterile;
Cabo Colnett, 13 July 1968, NCU 583170, cystocarpic; Punta
Baja, 12 July 1968, NCU 583171-73, cystocarpic.
REPRESENTATIVE SPECIMENS:
DESCRIPTION: Thalli 20–40 cm tall, crisp, yellowish-pink
or pink to bluish-red, consisting of one to many blades from
a stout discoid holdfast (Figs 32, 33); blades 20–30 cm
broad, simple, broadly obovate with a rounded apex or
sometimes irregularly split or truncate, generally entire; stipe
short, cylindrical, usually simple, lacking bladelets, merging
gradually into a prominent coriaceous, cuneate, concavoconvex apophysis 7–19 cm long; fertile blade rounded at the
apex, with the fertile portion papillate, 0.4–2.2 mm thick;
cortex 6–8 cell layers thick; medullary cells variable in size
and shape, 1.5–25 mm in diameter. Cystocarps 0.8–1.2 mm
in diameter, usually 2–3 in corymbose papillae on margins
and surfaces of the blade (Fig. 34); carpospores subspherical, 13–17 mm in diameter. Spermatangial sori superficial,
forming indefinite, irregularly anastomosing patches on the
thallus surface or borne on thin, crisped triangular-shaped
papillae with attenuated tips (Fig. 35). Tetrasporangial sori
r
Figs 28–31. Chondracanthus squarrulosus.
Fig. 28. Holotype of Grateloupia squarrulosa Setchell & Gardner, UC (Calif. Acad. Sci. 1368).
Fig. 29. Holotype sheet of Gigartina johnstonii Dawson, LAM (Dawson 436-40) in UC.
Fig. 30. Isotype material of Gigartina pectinata Dawson, LAM (Dawson 239-40) in UC.
Fig. 31. Isotype collection of Gigartina macdougalii Dawson, LAM (AHF 44) in UC.
144
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
200–325 mm in diameter, in soral patches circling the base of
slightly elevated, irregular to oblong mound shaped papillae
(Fig. 36); tetrasporangia 31–42 mm in diameter, in chains 6–
8 cells long.
Chondracanthus tepidus (Hollenberg) Guiry in
Hommersand et al. (1993, p. 115)
Fig. 37
Gigartina tepida Hollenberg (1945, p. 449).
(TYPE: Fig. 37. A collection by George J. Hollenberg on 8
December 1935 from the low littoral zone, Balboa, Orange
County, California. Housed in US under G. J. H. 1157, US
61184, barcode 00184810. The type sheet is tetrasporic and
contains 5 specimens.)
BASIONYM:
HETEROTYPIC SYNONYMS:
None.
145
The type consists of two specimens, one tetrasporic and the other
an immature specimen.)
Gigartina harveyana (Kützing) Setchell
& Gardner (1933, p. 276).
HETEROTYPIC SYNONYMS: Gigartina boryi Setchell & Gardner
(1933, p. 268). (TYPE: A cystocarpic plant UC 294525 and
a tetrasporangial plant UC 294522 collected by N.L. Gardner
from Pacific Grove, Monterey County, California.)
Gigartina microphylla (Harvey) Harvey (1853, p. 176, pl. 28, fig.
A). (BASIONYM: Rhodymenia ciliata var. microphylla Harvey
[1833, p. 164].) (TYPE: A specimen collected on Captain Beechey’s
Voyage from Monterey, Monterey County, California, in
November 1827. According to John Parnell, the type is not in
TCD.)
Gigartina radula (Esper) J. Agardh f. microphylla (Harvey)
Setchell 1899 in Phyc. Bor.-Amer. No. XIX.
HOMOTYPIC SYNONYM:
Harvey (1853, p. 176, pl. 28, fig. A, as
Gigartina microphylla); Setchell & Gardner (1933, p. 269, pls.
48, 49, as G. boryi); Smith (1944, pl. 67, fig. 2, as G. harveyana; pl.
68, fig. 1, as G. boryi); Dawson (1961, p. 268, pl. 50, fig. 3), after
Smith (1944, pl. 56, as G. harveyana); Abbott & Hollenberg
(1976, p. 521, fig. 468, as G. harveyana).
ILLUSTRATIONS:
Hollenberg (1945, p. 449, fig. 5, as Gigartina
tepida); Dawson (1961, p. 275, pl. 58, fig. 1, as G. tepida);
Abbott & Hollenberg (1976, p. 527, fig. 472, as G. tepida).
ILLUSTRATIONS:
HABITAT: On shells and rocks in sheltered and exposed
warm waters in the low intertidal.
Northern Washington (Scagel et al. 1986);
Oregon (Hansen 1997); Morro Bay, San Luis Obispo, California (Sparling 1977); Newport Bay, California (Hollenberg
1945); San Diego Mission Bay, San Diego, California.
DISTRIBUTION:
REPRESENTATIVE SPECIMENS: California: Holotype sheet
US 61184 (Fig. 37); San Diego, on rocks and attached to float,
inside entrance to Mission Bay, San Diego Co., 20 February
1946, NCU 583174-75, sterile.
DESCRIPTION: Thalli 3–5 cm high, soft, light brown to
purple, loosely tufted, irregularly or alternately branched
with or without a leading axis, apices of branches
sometimes attaching by accessory discs (Fig. 37); main
axes 0.5–1.0 mm in diameter, subcylindrical, terete to
mostly compressed, abundantly covered with distichous,
sharply pointed ultimate branchlets 1–5 mm in length.
Cystocarps 420–500 mm in diameter, mostly marginal on
the branches; carpospores subspherical, 18–26 mm in diameter. Spermatangia in small superficial sori. Tetrasporangial sori small, mostly marginal on axes and subultimate
branches, 150–230 mm in diameter; tetrasporangia 25–
32 mm diameter, in chains 4–6 cells long.
Chondracanthus harveyanus (Kützing) Guiry in
Hommersand et al. (1993, p. 115)
Figs 38–41
Mastocarpus harveyanus Kützing (1849, p. 734).
(TYPE: Fig. 38. A collection by Dr. T. Coulter, 1831–1833, from
Monterey, Monterey County, California, in Leiden, L941, 27 26!
BASIONYM:
HABITAT: Low intertidal to subtidal, associated with sand in
moderately sheltered sites.
DISTRIBUTION: Barkley Sound, Vancouver I., British Columbia
(Scagel 1973, p. 139); Ecola Pt., Clatsop Co., Oregon (Markham
and Celestino 1976, p. 261); Coos Bay, Oregon (Doty 1947, p. 181);
Tomales Bay, Marin Co., Calif. (Hughey 1995, p. 48); Monterey
Peninsula, Calif. (Smith 1944, p. 279, 282, as Gigartina boryi); La
Jolla, Calif. (Dawson 1945, p. 53); Punta Descanso, Cabo
Colonet, Punta Baja, Punta Marı́a, Baja Calif. (Dawson 1961,
p. 268).
REPRESENTATIVE SPECIMENS: California: Horseshoe Cove,
Sonoma Co., 5 October 1994, NCU 583176, tetrasporic; Dillon
Beach, Marin Co., 13 August 1977, NCU 583177, cystocarpic;
Greyhound Rock, San Mateo Co., 17 July 1996, NCU 583178-79,
cystocarpic and tetrasporic; Davenport Landing, Santa Cruz Co.,
9 August 1979, NCU 583180, cystocarpic; Pacific Grove,
Monterey Co., 21 August 1994, NCU 583181-83, tetrasporic; 11
July 1995, NCU 583184, male/cystocarpic and tetrasporic; Moss
Beach, Monterey Co., 19 August 1977, NCU 583185-87,
cystocarpic; Asilomar State Beach, Monterey Co., 26 July 1988,
NCU 583188, cystocarpic; Pebble Beach, Monterey Co., 20 July
1974, NCU 583189-90, cystocarpic; Mission Point, Monterey Co.,
17 July 1974, NCU 583191-92, tetrasporic; Carmel River State
Beach, Monterey Co., 14 July 1996, NCU 583193, tetrasporic;
Cambria, San Luis Obispo Co., 10 July 1996, NCU 563194,
tetrasporic; Goleta Beach, Santa Barbara Co., 24 August 1977,
NCU 583195, sterile; La Jolla, San Diego Co., 24 June 1945, M.H.
960, NCU 583196-99, male and tetrasporic; 1 May 1951,
M.H.1853, NCU 583200, cystocarpic; Hotel Del Coronado,
Coronado, San Diego Co., 22 August 1971, NCU 583201,
tetrasporic; Baja California: Punta Piedras, La Misión, 4–5
August 1968, NCU 583202-03, cystocarpic; August 1969, NCU
583204-05, male; Punta Descanso, 28 January 1968, NCU
583206, cystocarpic and male; 13 June 1968, NCU 583207,
r
Figs 32–36. Chondracanthus corymbiferus.
Fig. 32. Lectotype of Gigartina californica J. Agardh, LD 23933.
Fig. 33. Lectotype of Mastocarpus corymbiferus Kützing, L 941, 27 135.
Figs 34, 35. NCU 583407-08.
Fig. 34. Surface view showing corymbose cystocarpic papillae.
Fig. 35. Surface view showing male papillae.
Fig. 36. Surface view showing irregularly shaped tetrasporic papillae and location of tetrasporangial sori, NCU 583146-49.
146
Phycologia, Vol. 47 (2), 2008
Hughey & Hommersand: Systematics of Chondracanthus
cystocarpic; Punta Santo Tomás, 8 November 1969, NCU
583208-09, cystocarpic and tetrasporic; Isla San Martı́n, 12 June
1969, NCU 583210-12, cystocarpic and male; Cabo Colnett, 13
July 1968, NCU 583213-14, cystocarpic; 18 June 1972, NCU
583215-17, tetrasporic; Bahı́a Colnett, 2 July 1996, NCU 58321819, cystocarpic and tetrasporic; Punta Baja, 12 July 1968, NCU
583220-21, male; 3 July 1996, NCU 583222-23, cystocarpic and
tetrasporic.
DESCRIPTION: Thalli 30–40 cm tall, soft and felt-like,
consisting of one or more rusty to rose-red, ligulate blades
from a small discoid holdfast (Fig. 38); blades 2–7 cm wide
and simple, linear-lanceolate, gradually attenuated to
a point, or forming marginal outgrowths up to 4–5 mm
long, or proliferous, forming bladelets 3–10 cm long and
0.2–1 mm thick; stipitate, the stipe simple or forked,
narrowly cuneate to slender and compressed; margins and
surface of blades, except the base, covered more or less
densely with small, spinose papillae; cortex 4–6 cell layers
thick; medullary cells variable in size and shape, 1.5–16 mm
in diameter. Cystocarps 300–500 mm in diameter, solitary
and pedicellate in the superficial outgrowths that tend, in
part, to be flattened or blade-like, or basal, two per papilla,
on simple, narrow attenuated papillae (Fig. 39); carpospores subspherical, 12–18 mm in diameter. Spermatangial
sori superficial, indefinite on the bases and blades of
slender, elongate papillae terminated by thin acute tips
(Fig. 40). Tetrasporangial sori small, 250–350 mm diameter,
ellipsoidal, laterally positioned on elongate papillae
(Fig. 41); tetrasporangia 38–47 mm in diameter, forming
linear rows 6–9 tetrasporangia cells long; released through
a pore in the outer wall.
Chondracanthus bajacalifornicus Hughey &
Hommersand, sp. nov.
Figs 42–50
TYPE: Figs 42–44. A collection by Max H. Hommersand from the
SE side, Punta Baja, Baja California, Mexico, 21.vi.1974, UC
1819313, cystocarpic, male, and mixed-phase male/tetrasporic
plants.
ETYMOLOGY: The specific epithet refers to the geographical
state Baja California, Mexico, which is the center of distribution
for this species.
ILLUSTRATIONS:
None previously published.
HABITAT: Saxicolous, exposed to surf and swift flowing currents
often forming an extensive turf in the mid-low intertidal.
DISTRIBUTION: San Diego, California to Punta Conejo, Baja
California, Mexico.
REPRESENTATIVE SPECIMENS: California: San Diego Mission
Bay Jetty, San Diego Co., California, 24 December 2006, NCU
583224, cystocarpic; Baja California: Punta Piedras, La Misión,
147
18 January 1969, NCU 583225, cystocarpic; Punta Descanso, 13
June 1968, NCU 583226-28, cystocarpic and male; La Bufadora,
Punta Banda, 6 July 1996, NCU 583229-30, cystocarpic and
male; Punta Banda, 2 July 1969, NCU 583231-33, cystocarpic
and male; Punta Santo Tomás, 8 November 1969, NCU 58323436, cystocarpic and male; 2 July 1996, NCU 583237-39,
cystocarpic and male; Cabo Colnett, 18 June 1972, NCU
583240-41, cystocarpic; Isla San Martı́n, 12 June 1969, NCU
583409, sterile; Punta Baja, 21 June 1974, UC 1819313,
cystocarpic, male and male/tetrasporic; 12 July 1968, NCU
583242-44, cystocarpic and male; 3 July 1996, NCU 583245,
cystocarpic; Punta Maria, 23 June 1974, NCU 583246-47,
cystocarpic and male; Punta Santa Rosalillita, 16 June 1972,
NCU 583248-49, cystocarpic and male; Punta Negra, 22 June
1974, NCU 583250-51, cystocarpic and male; Punta Asunción, 10
June 1972, NCU 583252, cystocarpic and male; Punta Conejo, 1
June 1972, NCU 583253-54, cystocarpic and male.
LATIN DIAGNOSIS: Thalli 6–12 cm alti cartilaginei, luteoli vel
brunneo-rubri vel purpureo-nigri, facientes fasciculos rigidos
dense ramosos ex haptero discoideo basi stolonifero orientes;
caules erecti tereti vel compressi 1–2 mm lati, plerumque ad basin
ramosi axibus longis aut simplicibus aut semel vel bis furcatis,
axibus vegetativis nudi, demum supra arcte circumdata undique
ramulis brevibus ramosis vel pinnulis in thallis fertilibus; cortex
stratorum cellularum 7–8, cellulis medullariis magnitudine
formaque variabilibus, 1.5–17 mm in diametro. Cystocarpia
papillata 665–875 mm in diametro, portata in pinnulis in ramulis
congestis aut simplicibus aut semel vel bis furcatis in summa
parte tertia axium, nuda vel spinis brevibus circum ostiolum
armata; carposporae subsphaericae 15–25 mm in diametro.
Plantae spermatangiales plumosae, ramulis distiche ramosis vel
complanatis ut videtur echinatis. Sori tetrasporangiales 140–
280 mm in diametro, irregulariter dispositi in ramulis bis vel ter
distiche divisis; tetrasporangia angusta ellipsoidalia 12–15 mm
lata 22–30 mm longa, in catenis 4–6 cellulas longis facta.
DESCRIPTION: Thalli 6–12 cm high, cartilaginous, yellowish to brownish red or purplish black, forming stiff, densely
branched clumps arising from a discoid holdfast that is
stoloniferous at the base (Figs 42–46); erect shoots terete to
compressed, 1–2 mm wide, typically branched at the base
with long axes that are either simple or once or twice forked
above, vegetative axes naked, becoming densely crowded
on all sides above by short, branched ramuli or bladelets in
fertile thalli; cortex of 7–8 layers of cells, medullary cells
variable in size and shape, 1.5–17 mm diameter. Cystocarps
papillate, 665–875 mm in diameter, borne in bladelets on
crowded simple or 1–2 times forked branchlets in the
upper 1/3 axis, and naked or armed with short spines
around the ostiole (Figs 47, 48); carpospores subspherical,
15–25 mm in diameter. Spermatangial plants feathery, with
distichously branched or flattened ramuli that appear
echinate (Figs 43, 49). Tetrasporangial sori 140–280 mm in
diameter, irregularly distributed on 2–3 times distichously
divided branchlets (Fig. 50); tetrasporangia narrow, ellipsoidal, 12–15 mm broad by 22–30 mm long, formed in
chains 4–6 cells long.
r
Figs 37–41. Chondracanthus tepidus and C. harveyanus.
Fig. 37. Holotype of Gigartina tepida Hollenberg, US 61184. 38-41. Chondracanthus harveyanus.
Fig. 38. Lectotype of Mastocarpus harveyanus Kützing, L 941, 27 26.
Figs 39, 41. NCU 583183.
Fig. 39. Surface view showing elongated papillae with mature cystocarps at the bases.
Fig. 41. Surface view of elongated tetrasporic papillae with 1-2 laterally located elliptical sori.
Fig. 40. Surface view of feathery male papillae, NCU 583204-05.
148
Phycologia, Vol. 47 (2), 2008
Chondracanthus kjeldsenii Hughey & Hommersand, sp. nov.
Figs 51–55
Figs 51–53. A collection by Ann Belovich from Scorpion
Anchor, Santa Cruz I., California, 12 August 1969, UC 1819314,
cystocarpic and male plants; isotype in NCU wet collection as
UC 1819314.
TYPE:
ETYMOLOGY: The specific epithet is in honor of Chris K.
Kjeldsen, a dedicated teacher of biology and skilled identifier of
marine algae.
ILLUSTRATIONS:
None previously published.
HABITAT: Saxicolous, protected habitats, found in swift flowing
currents near the entrance of bays, mid-low intertidal.
DISTRIBUTION: Channel Islands to San Diego Mission Bay, San
Diego, California.
REPRESENTATIVE SPECIMENS:
California: Santa Cruz I., UC
1819314.
Thalli 6–20 cm alti cartilaginei, pallide
brunnei rubro-purpurei vel nigri, facientes fasciculos dense
ramosos ex haptero discoideo; caules erecti in thallis juvenilibus
infra dichotome ramosi, in maturis compressi axibus conspicuis
2–4 mm latis, pinnatim vel irregulariter ramosi, ramis imbricatis
proliferis ramulisque echinatis dense tecti. Cortex stratorum
cellularum 7–8, cellulis medullariis variabilibus 1.5–15 mm latis.
Cystocarpia 500–800 mm in diametro, in axibus spinosis complanatis portata vel in ramulis lateralibus pedicellata; carposporae subsphaericae 12–18 mm in diametro. Plantae spermatangiales fruticosae, spermatangiis in ramulis dense ramosis portatis.
Tetrasporangia non visa.
LATIN DIAGNOSIS:
DESCRIPTION: Thalli 6–20 cm high, cartilaginous, light
brown, reddish purple or black, forming densely branched
clumps from a disc shaped holdfast; erect shoots dichotomously branched below in juveniles, compressed with
conspicuous, 2–4 mm wide axes in mature thalli, pinnately
to irregularly branched, densely covered with overlapping
proliferous branches and echinate ramuli. Cortex of 7–8
layers of cells, medullary cells variable, 1.5–15 mm wide.
Spermatangial plants bushy, spermatangia borne on
densely branched ramuli. Cystocarps 500–800 mm in diameter, borne on spiny, flattened axes or pedicellate on
lateral branchlets; carpospores subspherical, 12–18 mm in
diameter. Tetrasporangia not observed.
Chondracanthus serratus (Gardner) Hughey & Hommersand,
comb. nov.
Figs 56–62
Gigartina serrata Gardner (1927, p. 334, pls. 60–62.
(TYPE: Fig. 56. A collection by N.L. Gardner in July 1924 from
Ensenada, Baja California, UC 296698! [tetrasporic] and 296699!
[cystocarpic]; isotype, Gardner 4958! [cystocarpic].)
BASIONYM:
HETEROTYPIC SYNONYM: Gigartina canaliculata f. laxa F.S.
Collins (1906, p. 111). (TYPE: A collection by Mrs. E. Snyder
washed ashore, La Jolla, California, Phyc. Bor.-Amer. No. 1139
in the general collection at the Farlow Herbarium.)
Gardner (1927, p. 334, pls. 60–62); Dawson
et al. (1960, p. 60, pl. 30, figs. 2, 3); Dawson (1961, p. 274, pl. 62);
Abbott & Hollenberg (1976, p. 518, fig. 465, above left, as
Gigartina canaliculata).
ILLUSTRATIONS:
HABITAT: Saxicolous in low intertidal in swift flowing currents
near the entrance of bays.
DISTRIBUTION: Balboa (Setchell & Gardner 1933, p. 264) to San
Diego, California (Dawson 1945, p 52), and into Baja California
to 15 kilometers south of Punta Eugenia, Mexico.
REPRESENTATIVE SPECIMENS: California: La Jolla, San Diego
Co., date unknown, P.B.A. 1139, NCU 583255, cystocarpic; 22
October 1944, NCU 583410, male; 29 July 1969, NCU 583256,
sterile; 23 November 1944, NCU 583257, cystocarpic; Mission
Bay Jetty, San Diego, California, J.R., P.A. & D.R. Hughey, 17
March 1999, NCU 583258-65, cystocarpic, male, tetrasporic;
Ocean Beach, San Diego Co., 19 January 1969, NCU 583266,
cystocarpic; Reef below College of the Nazarene, Point Loma,
San Diego Co., 20 June 1969, NCU 583267-68, tetrasporic and
sterile; Lighthouse at Point Loma, San Diego Co., 26 January
1968, NCU 583269-70, cystocarpic and tetrasporic; 16 January
1969, NCU 583271-72, cystocarpic and tetrasporic; Hotel Del
Coronado, Coronado, San Diego Co., 16 December 1945, M.H.
1178, NCU 583273-74, cystocarpic; Baja California: Ensenada,
UC 296698-99; Ensenada, July 1924, Gardner 4958, LAM in UC,
tetrasporic; Punta Baja, 21 June 1974, NCU 583275, male; 2
miles S. of Punta Eugenia, 11 June 1972, NCU 583276, sterile; 10
miles S. of Punta Eugenia, 12 June 1972, NCU 583277,
cystocarpic and tetrasporic.
DESCRIPTION: Thalli 14–30 cm high, consisting of few to
many coarse, cartilaginous, dark purplish red shoots from
a crustose stoloniferous base (Figs 56, 58, 60, 61); erect
shoots usually greater than 2 mm in diameter, terete
throughout, usually forked once or twice 4–9 cm above
the base into several main branches that are irregularly
dichotomously to oppositely branched 2–4 more times;
lower axes naked; upper branches provided on all sides at
more or less regular intervals with simple or branched
fructiferous ramuli of variable thickness; cortex 7–8 cell
layers thick; medullary cells variable in size and shape, 1.5–
17 mm in width. Cystocarps 400–700 mm in diameter,
mostly forming dense pedicellate clusters at intervals on
lateral branches (Figs 57, 62); carpospores 12–18 mm in
diameter. Spermatangial plants sparsely branched, lacking
papillae, gracilariod in appearance (Fig. 60). Tetrasporangial sori 150–300 mm in diameter, widely scattered in ramuli
that point upward (Fig. 59); tetrasporangia 32–41 mm
diameter, formed in chains 5–7 cells long.
Chondracanthus canaliculatus (Harvey) Guiry in
Hommersand et al. (1993, p. 115)
Figs 63–66
BASIONYM: Gigartina canaliculata Harvey (1841, p. 409). (TYPE:
Fig. 63. A collection by David Douglas from San Francisco,
California, in 1831 in Herb. Harvey at TCD. The type consists of
two clumps and a fragment of a cystocarpic specimen; see
Fig. 63.)
Harvey (1853, p. 174, pl. 27, fig. C); Smith
(1944, p. 278, pl. 69, fig. 3); Dawson (1961, p. 266, pl. 54, fig. 1);
Abbott & Hollenberg (1976, p. 518, fig. 464, below right, as G.
canaliculata).
ILLUSTRATIONS:
HABITAT:
Saxicolous in mid-high intertidal on exposed coasts.
DISTRIBUTION: Cape Arago, Oregon (Doty 1947, p. 181);
Monterey Peninsula, Calif. (Smith 1944, p. 278); San Luis
Obispo Co., Calif. (Sparling 1977, p. 68); Channel Is., Calif.
(Murray 1974, p. 46); La Jolla, Calif. (Dawson 1945, p. 52); S.
side Punta Descanso, Punta Banda, Punta Baja, Isla Cedros,
Punta San Eugenio, to Isla Magdalena, Baja Calif. (Dawson
1961, p. 266).
California: Devil’s Gate, Humboldt Co., 31 July 1965, E.Y.D. 25499, NCU 583278, sterile;
REPRESENTATIVE SPECIMENS:
Hughey & Hommersand: Systematics of Chondracanthus
149
Figs 42–50. Chondracanthus bajacalifornicus Hughey & Hommersand sp. nov.
Figs 42–44. Holotype, UC 1819313.
Fig. 42. Cystocarpic plant.
Fig. 43. Spermatangial plant.
Fig. 44. Mixed-phase plant with spermatangia and tetrasporangial sori.
Fig. 45. Juvenile plant without fertile branchlets, NCU 583409.
Fig. 46. Cystocarpic plant (sequenced), NCU 583245.
Fig. 47. Young simple bladelet with cystocarps, NCU 583229-30.
Fig. 48. Forked bladelet with mature cystocarps, from plant figured in Fig. 47.
Fig. 49. Branchlet bearing spermatangia, collection data as in Fig. 47.
Fig. 50. Mixed-phase male and tetrasporangial branchlet with spermatangia and tetrasporangial sori (dark patches), from plant in
Fig. 44.
150
Phycologia, Vol. 47 (2), 2008
Figs 51–55. Chondracanthus kjeldsenii Hughey & Hommersand sp. nov. Figs 51–55. Holotype, UC 1819314 and isotype in NCU wet
collection as UC 1819314.
Fig. 51. Cystocarpic plant.
Fig. 52. Sterile plant.
Fig. 53. Juvenile plant.
Fig. 54. Branchlet with mature cystocarps.
Fig. 55. Male plant with spermatangia.
Hughey & Hommersand: Systematics of Chondracanthus
151
Figs 56–62. Chondracanthus serratus (Gardner) Hughey & Hommersand comb. nov.
Fig. 56. Cystocarpic specimen from the holotype sheet of Gigartina serrata Gardner, UC 296699.
Fig. 57. Enlarged view of segment from plant in Fig. 56 showing cystocarps.
Fig. 58. Tetrasporic plant from the holotype sheet of Gigartina serrata, UC 296698.
Fig. 59. Enlarged view of segment from plant in Fig. 58.
Fig. 60. Male plant bearing spermatangia, NCU 583410.
Fig. 61. Tetrasporangial plant bearing tetrasporangia on indeterminate branches and determinate laterals, NCU 583258-65.
Fig. 62. Lateral branchlet bearing clusters of cystocarps, NCU 583269-70.
Horseshoe Cove, Sonoma Co., 20 June 1966, NCU 583279,
sterile; Dillon Beach, Marin Co., 13 August 1977, NCU 583280,
sterile; Moss Beach, San Mateo Co., 16 October 1940, NCU
583281, cystocarpic; Greyhound Rock, San Mateo Co., 17 July
1996, NCU 583282, sterile; Davenport Landing, Santa Cruz Co.,
9 August 1979, NCU 583283, male and sterile; Pebble Beach,
Monterey Co., 20 July 1974, NCU 583284, sterile; Montana de
Oro State Park, San Luis Obispo Co., 19 July 1966, NCU
583285, sterile; Cambria, San Luis Obispo Co., 10 July 1996,
NCU 583286, sterile; Jalama Beach County Park, Santa Barbara
Co., 21 July 1966, NCU 583287, cystocarpic and sterile; Goleta
Beach, Santa Barbara Co., 24 August 1977, NCU 583288,
cystocarpic; Hendry’s Beach, Santa Barbara Co., 16 May 1941,
E.Y.D. 864, NCU 583289, cystocarpic; White’s Pt., Los Angeles
Co., 27 December 1945, E.Y.D. 761, NCU 583290, cystocarpic
and tetrasporic; White’s Pt., Los Angeles Co., 31 July 1979, NCU
583291-95, cystocarpic and tetrasporic; La Jolla Shores, San
Diego Co., 24 December 1995, NCU 583296, sterile; La Jolla,
San Diego Co., 25 August 1945, M.H. 1095, NCU 583297,
sterile; 13 May 1951, NCU 583298, sterile; June 1968, NCU
583299, cystocarpic; Bird Rock, La Jolla, San Diego Co., 23 June
1946, NCU 583300, cystocarpic; Ocean Beach, San Diego Co.,
August 1968, NCU 583301, cystocarpic; Reef below College of
the Nazarene, Point Loma, San Diego Co., 16 January 1969,
NCU 583302, sterile; Baja California: Punta Piedras, La Misión,
4–5 August 1968, NCU 583303, sterile.
DESCRIPTION: Thalli up to 25 cm tall, cartilaginous,
yellow-green to purple-black, densely clumping, consisting
152
Phycologia, Vol. 47 (2), 2008
Figs 63–68. Chondracanthus canaliculatus (Harvey) Guiry and C. intermedius (Suringar) Hommersand.
Figs 63–66. C. canaliculatus.
Fig. 63. Lectotype of Gigartina canaliculata Harvey, TCD.
Fig. 64. Cystocarpic specimen, G.M.S. #41-189 in UC.
Fig. 65. Lateral branch bearing young and mature cystocarps, NCU 583287.
Fig. 66. Robust plant from an exposed habitat, NCU 583286.
Figs 67, 68. Chondracanthus intermedius, E.Y. LAM (Dawson 18651) in UC.
Fig. 67. Specimen with recurved branches and holdfast-forming branches.
Fig. 68. Irregularly branched specimen with narrow branches.
of several to many erect shoots from a primary disc-shaped
holdfast (Figs 63, 64, 66); later abundantly stoloniferous;
erect shoots subcylindrical, 0.5–2 mm wide, pinnate to
irregularly dichotomously branched, the upper third abundantly provided with short, distichous, determinate, simple
or mostly compound spinulose branchlets 1–3 mm long and
variable in thickness; cortex 7–8 cell layers thick; medullary
cells variable in size and shape, 2–20 mm wide. Cystocarps
700–950 mm in diameter, globose, solitary on simple spinose
pinnules, or compound in groups on large, protruding,
echinate ramuli (Fig. 65); carpospores subspherical, 12–
20 mm in diameter. Spermatangia slightly nemathecial in
surface cortical layers on thin, crisped, feathery, triangularshaped terminal pinnules with attenuated tips. Tetrasporangial sori 100–300 mm in diameter, borne on all sides in
upwardly pointing determinate ramuli or pinnules that vary
from short (3–5 mm) densely crowded and abruptly acute to
long (2–3 cm) widely scattered forms with 2–3 sharp teeth,
or unbranched and subulate; tetrasporangia 34–45 mm
diameter, formed in chains 4–6 cells long.
Chondracanthus intermedius (Suringar) Hommersand in
Hommersand et al. (1993, p. 115)
Figs 67, 68
BASIONYM: Gigartina intermedia Suringar 1870: 30, pl. 17B.
(TYPE: A collection by C.J. Textor on 8 December 1935 from the
Sea of Japan.)
HETEROTYPIC SYNONYMS: None.
ILLUSTRATIONS:
HABITAT:
Dawson (1961, p. 268, pl. 54, fig. 2).
Saxicolous in the low intertidal.
DISTRIBUTION: Japan (Yoshida et al. 1990, as Gigartina intermedia; Yoshida 1998; Titlyanov et al. 2006); China (Tseng 1984,
as G. intermedia; Xia & Zhang 1999); Vietnam (Pham-Hoàng
1969, as G. intermedia; Tsutsui et al. 2005); Taiwan (Huang
Hughey & Hommersand: Systematics of Chondracanthus
2000); New South Wales (Millar 1990; Millar & Kraft 1993);
Queensland (Phillips 1997, 2002); Chile (Silva & Chacana 2005);
Gulf of California: Isla Tortuga and Mazatlán, Sinaloa (Dawson
1961).
Gulf of California: Isla Tortuga,
26 April 1958, LAM (E.Y.D. 156181) in UC, cystocarpic;
Algodones Beach, Guaymas, Sonora, 8 March 1978, NCU
583304, sterile.
REPRESENTATIVE SPECIMENS:
DESCRIPTION: Thalli 2–3 cm high, cartilaginous, purplish
red to black with a bluish iridescence, forming low,
pulvinate, densely overlapping masses widely spread over
rocks, firmly attached to the substrate by tips of branches
that act as holdfasts, irregularly branched (Figs 67, 68);
axes 1–2 mm in width; branches 0.5–1.5 mm in diameter,
8–12 mm long, often dilated to 2 mm or more forming
sublanceolate segments ending in sharp points, strongly
recurved. Cystocarps about 1 mm in diameter, mostly
marginal on the branches of all orders.
REMARKS: Dawson’s material from Isla Tortuga and the
small, sterile thalli with arcuately arranged branches in our
collection from Algodones Beach, Sonora, we are tentatively treating as conspecific with its western Pacific
counterpart. This species in the Gulf of California requires
further investigation.
ACKNOWLEDGEMENTS
We particularly wish to thank Fran Hommersand for
assembling specimens for accessioning. We express our
gratitude to Paul Silva for editorial assistance with the
introductory nomenclatural history on the Gigartinaceae.
We express thanks to Ken Ishida, Mitsunobu Kamiya,
Wilson Freshwater, and an anonymous reviewer for
editorial suggestions. We also thank Suzanne Fredericq
for graciously supplying DNA from previous rbcL studies.
We sincerely thank Ann Belovich, Steven Murray, Sandra
Lindstrom, Pat and David Hughey for collecting specimens,
and Kathy Ann Miller for snippets of C. kjeldsenii. We are
indebted to Geoffrey Leister, Richard Moe, Ingrid Pol-Yin
Lin, Kathy Ann Miller, Susanna Riebe, John Parnell, and
Genevieve Lewis-Gentry for scanned images. We are most
gracious to Per Lassen for sending a fragment of G.
californica and for lectotypification assistance. Franchesca
Perez and Miguel Volovsek lended help with DNA
sequencing. Rangasamy Elumalai, Len Krall, and Punita
Nagpal gave technical assistance, and Jason Reed, Cliff
Parks, and George Stamatoyannopoulos offered work space
in their laboratories. We greatly appreciate Mark Garland
for the latin diagnoses. This project was supported in part by
a Cooley Trust Scholarship and Coker Fellowship from the
Department of Biology at the University of North Carolina,
Chapel Hill and the Hans & Margaret Doe Charitable Trust
Scholarship Foundation.
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