Candelaria concolor - a rare lichen in the Nordic countries
MARTIN WESTBERG and ULF ARUP
Westberg, M. & Arup, U. 2010: Candelaria concolor – a rare lichen in the Nordic
countries. Graphis Scripta 22: 38–42. Stockholm. ISSN 0901−7593.
Candelaria concolor was recently revised and the majority of the Scandinavian
collections was found to belong to C. pacifica. Candelaria concolor is a rare species with
a southwestern distribution in the Nordic countries. It is growing on deciduous trees in
open landscapes. Maps of the distribution of the two species in the Nordic countries are
presented.
Martin Westberg, Swedish Museum of Natural History, Cryptogamic Botany, P. O. Box
50007, SE-104 05 Stockholm, Sweden. E-mail: Martin.Westberg@nrm.se
Ulf Arup, Botanical Museum, Lund University, Östra Vallgatan 18, SE-223 61 Lund,
Sweden. E-mail: Ulf.Arup@botmus.lu.se
Candelaria concolor has until now been known
as a common and familiar lichen in the Nordic
countries. Recently, however, the superficially
similar species Candelaria pacifica M.Westb.
& Arup was described (Westberg & Arup in
print). During that investigation we realized
that the vast majority of the Nordic material
accumulated under the name C. concolor in the
herbaria belong to C. pacifica. Candelaria
concolor, on the other hand, surprisingly turned
out to be a rare species and only a handful of
mainly older specimens from Sweden and
Norway were found in Swedish herbaria. An
extended investigation of herbarium material in
other Nordic herbaria resulted in a few finds
from Denmark and several additional localities
in Norway. Our efforts to find the species in the
field in Sweden have been unsuccesful and our
conclusion is that C. concolor is a rare lichen in
the Nordic region. It is included in the Swedish
Red List as Data Deficient (DD) (Gärdenfors
2010). In this paper we present the current
knowledge of the distribution and ecology of C.
concolor in the Nordic countries.
Identification
The main distinguishing characters between C.
concolor and C. pacifica is that the former has
polyspored asci and a thallus that possess a
lower cortex, whereas C. pacifica has 8-spored
asci and a thallus that lacks a lower cortex.
When fertile, the species are thus easily
separated. Unfortunately, Candelaria pacifica
has never been found fertile in the Nordic
countries and only two of the specimens of C.
concolor had apothecia. When well-developed,
however, both species have a characteristic
appearance. Candelaria concolor is usually
larger and more distinctly lobate, with branched
lobes with a smooth, flattened surface, forming
small, adnate rosettes (Fig. 1). Under the
dissecting microscope the lower side is shiny,
whitish (in the herbaria turning pinkish in older
specimens) and with well-developed, sometimes numerous rhizines. Candelaria pacifica is
usually composed of very small, raised,
squamule-like lobes (Fig. 2) but often appears
like a granular-blastidiate crust with few
distinct and well-developed lobes. The lower
GRAPHIS SCRIPTA 22 (2010)
Candelaria concolor, a rare lichen 39
Figure 1. Candelaria concolor. Norway, Johnsen (BG L-86701). Bar = 1 mm.
side of C. pacifica has an arachnoid appearance
with a whitish or greenish colour as the green
algae shines through. A few short rhizine-like
structures are often found. As the lobes are
often very small and poorly developed the
absence of a lower cortex is not always an easy
character to use. Candelaria concolor can also
easily be confused in the field with green
morphs of Xanthoria spp. growing in the shade
but the K+ blood-red reaction of Xanthoria is
distinctly different from the K– or faint K+
brick-red to orange reaction of C. concolor.
Candelaria concolor (Dicks.) Stein
Candelaria concolor is apparently rare but
widespread in southern Scandinavia and has a
southwestern distribution with a number of
outlying localities in southeastern Norway and
east central Sweden (Fig. 3). It grows on
deciduous trees, apparently in open situations.
The most common phorophytes in Scandinavia
appear to be Acer pseudoplatanus (26% of the
localities), Fraxinus excelsior (24%), Malus
spp. (14%) and Ulmus glabra (9%) and it is
also known from Salix fragilis, Tilia cordata,
Sorbus aucuparia, Acer platanoides, and
Fagus sylvatica. The fertile specimens were
collected in Sweden, Närke, 1889 and in
Norway, Akershus, 1944. Only two of the old
localities in Sweden have been visited (Skåne
and Närke) but the species has been searched
for during numerous excursions in southern
Sweden without success. Its current status is not
known but it seems to be very rare in Sweden.
In Norway, however, the species is apparently
more common and it has been searched for and
found recently (L. Lindblom, pers. comm.) and
there are several herbarium collections from
Rogaland and Hordaland from recent years. In
Denmark a few old specimens were found but
from Finland there are no finds at all.
Candelaria concolor is easily overlooked
because of its similarity to C. pacifica and the
40 Martin Westberg & Ulf Arup
GRAPHIS SCRIPTA 22 (2010)
Figure 2. Candelaria pacifica. Sweden, Arup L01516 (LD). Bar = 1 mm.
species has to be searched for actively before it
can be evaluated for the Red Lists.
Specimens examined from the Nordic
countries: Denmark. Jutland: LI Emmerske, E
of Tønder. 17 July 1975, Søchting (C).
Sjælland: W of Slagelse landevej, 4 April 1920,
Mathiesen (C); Østrup, W of Uggerløse, Distr.
44, 17 Oct. 1940, Gelting (C); Orup, S of Fakse
Distr. 39b, 1 Aug. 1940, Gelting (C); Glim SW.
15 May 1938, Skytte-Christiansen (C);
Norway. Akershus: Bærum, 13 Feb. 1944, Rui
5211 (O L-55381; L-55391); Ås, 12 Sept.
1999, Bratli 3033 (O L-39497); Asker, 6 June
1937, Rui (O L-55382); Prope Christianiam,
[undated], Norman (BG L-8304, L-8305).
Aust-Agder: Valle, 23 July 1981, Nordnes 403
(O L-56061); Valle, 5 June 1955, Degelius
(UPS L-068411); Setesdalen, 5 June 1955,
Degelius (O L-56063). Buskerud: Ringerike, 7
June 2005, Timdal 9922 (O L-136633).
Hordaland: Granvin, 2 July 1915, Havaas &
Lynge (O L-56183), 3 July 1932, Degelius
(UPS L-068416); [Kvam,] Strandebarm, 1916–
1920, Lillefosse (O L-56166, L-56167, L56169; BG L-8306, L-8307, L-8308, L-8309,
L-8310, L-8311, L-8312, L-8313, L-8314, L8315, L-8316, L-8317. Oppland: Ringebu, 19
June 1948, Ahlner (O L-56021); Vang, 7 Aug.
1971, Degelius (UPS L-068415). Rogaland:
Finnøy, 1 April 1971, Østhagen 39 (O L56131, L-56132); Finnøy, 24 May 2008,
Johnsen (BG L-86829); Bjerkreim, Aug. 1977,
Jølle (O L-56129); Klepp, 1976–1978, Balle
(BG L-8300, L-8301, L-8302); Hjelmeland, 12
July 1947, Degelius (O L-56076, UPS L068413); 26 May 2009, Johnsen (BG L87417); [Stavanger] Hetland, 2 Jan. 1948, Dahl
(O L-56134); Strand, 14 Aug. 2008, Blom
(BG), 13 Aug. 1998, Krumsvik (BG L-39431);
Sandnes, 28 June 1970, Jørgensen 3262 (UPS
L-145175); Stavanger, 5 March 2002 & 5 June
2008, Johnsen (BG L-86701, L-74033);
GRAPHIS SCRIPTA 22 (2010)
Figure 3. The known distribution of C.
concolor in the Nordic countries
Rennesøy, 10 Nov. 2002 & 20 May 2008,
Johnsen (BG L-75959, L-86688); Sola, 30 Nov
2002, Johnsen (BG L-75832). Sogn og
Fjordane: Stryn, 16 July 2006, Løfall bpl11119 (O L-147765); Luster, 18 July 2002,
Lindblom & Blom L248 (BG L-76821).
Telemark: Tinn, 6 Sept. 1999, Løfall bpl-5914
(O L-43876). Vestfold: Lardal, 23 March 1967,
Ryvarden (O L-56029). Sweden. Närke:
Knista, 1889, Hellbom (UPS L-137432, S
L55921). Skåne: Mölleberga par, 19 July 1937,
Degelius (UPS L-068389). Södermanland:
Lilla Malma par., 1887, Blomberg (UPS L145171). Västergötland: Askim par., 19 Feb.
1962, Tibell 269 (UPS L-145172), V. Frölunda
par., 21 May 1933, Magnusson 13945 (UPS L145173), Skepplanda par., Vadbacka, 1 Oct.
1926, Magnusson 10312 (UPS L-145174);
Falköping, Sept. 1921, Vrang (S L55922, S
L55923).
Candelaria concolor, a rare lichen 41
Figure 4. The known distribution of C.
pacifica in the Nordic countries
Candelaria pacifica M.Westb. & Arup
Very reduced forms of C. pacifica can be
confused with the small, granular or sorediate
species of Candelariella, in particular with C.
efflorescens but usually a few larger lobes are
found in C. pacifica. For a more detailed
description of C. pacifica see Westberg & Arup
(2010). Candelaria pacifica is a common
species widely distributed in southern
Scandinavia with scattered localities in the
boreal zone reaching northern Sweden (Fig. 4).
It has been noted on many different
phorophytes but it usually grows on deciduous
trees and is sometimes also found on wood.
Acknowledgements
The study was finalized thanks to support to
MW from The Swedish Taxonomy Initiative
(Svenska Artprojektet), administered by the
Swedish Species Information Centre (ArtDatabanken). We are greatful to the curators of
42 Martin Westberg & Ulf Arup
LD, S, UPS, C, BG, O and H for loan of
material. Thanks to Louise Lindblom and Hans
Blom for contributory field work in Norway.
GRAPHIS SCRIPTA 22 (2010)
Westberg, M. & Arup, U. Candelaria
pacifica (Ascomycota, Candelariales) and
the identity of C. vulgaris. Bibliotheca
Lichenologica (in print).
References
Gärdenfors, U. (ed.) 2010. Rödlistade arter i
Sverige 2010 – The 2010 Red List of
Swedish Species. ArtDatabanken, SLU,
Uppsala.
NLF meeting 2011 in Dubingiai, Lithuania
On 19–23 September 2011 the Nordic Lichen Society will organize a
lichenological meeting at Dubingiai Recreation and Conference Center
(http://www.litorina-dubingiai.lt/lt/dubingiai/dubingiai.php), located c. 50
km NE of Vilnius (Lithuania). The Center is situated in Asveja Regional
Park in the lake district of eastern Lithuania, an area with diverse nature –
old-growth forests, swamps and traditional rural landscape.
The meeting will be combined with the Baltic Symposium of Mycologists
and Lichenologists. The number of participants is not limited. Further
information is available at http://www.botanika.lt. Contact person for
inquiries: Jurga Motiejūnaitė (jurga.motiejunaite@botanika.lt).