SPECIES FACT SHEET
Common Name: Three-ranked knob moss, California triquetrella moss
Scientific Name: Triquetrella californica
Division: Bryophyta
Class: Bryopsida
Order: Pottiales
Family: Pottiaceae
Technical Description: Plants ascending or trailing, stems 1-3 cm long,
branched irregularly, the branches threadlike, 0.5-0.75 mm wide. Stems
triangular in cross-section. Leaves yellow-green to yellowish-brown,
decurrent, straight and imbricate when dry, with flexuose tips,
lanceolate. When wet, leaves erect-spreading to squarrose, in three
longitudinal rows, the rows straight or spiraling up the stem, but this
character is not obvious on dry plants. Costa prominent at back of leaf.
Margins of leaves conspicuously recurved, crenulate because of
projecting papillae. Leaf cells rounded, thick-walled, with tall, often
forked papillae. Leaf color reaction orange to yellowish orange in KOH
(Zander 1980, 2002). Plants dioicous; male plants and capsules have not
been found. Distinctive characters: (1) Leaves, when wet, spiraling up
the stem in three distinct rows, (2) the leaf cells with tall, often forked
papillae. Similar species: The sterile leafy plants of Triquetrella have
been confused with other genera in the Pottiaceae. Didymodon vinealis
and its many varieties, also occurring on soil in open areas, range in
color from yellow-green to reddish to blackish. When dry, its leaves are
contorted, and when wet, they lack the distinctive three-ranked habit
exhibited by Triquetrella. Didymodon ferrugineus (= D. fallax var. reflexus)
is similar to Triquetrella but its (1) stem is round in cross-section, (2) leaf
margins are not crenulate and only weakly recurved, (3) leaves are 3-5
ranked, and (4) in the Pacific Northwest it is not known south of British
Columbia. Other descriptions and illustrations: Grout 1938: 170;
Zander 1980: 230; Casas et al. 1993: 126; Christy and Wagner 1996:
VII-87; Zander 2002; Game 2004.
Life History: Details not documented. Protonema inconspicuous,
forming buds and shoots in usual fashion of moss growth and
development. Plants with capsules should be sought. If male plants and
capsules do not exist, populations are limited to vegetative reproduction
and dispersal. This condition implies lower genetic diversity and slower
rates of dispersal and colonization than in species producing spores.
Populations limited to vegetative reproduction can be locally abundant
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but are at risk of catastrophic loss at particular localities and limited
means of movement into new habitats.
Range, Distribution, and Abundance: Endemic to western North
America. Known only from scattered localities near the coast,
southwestern Oregon to southern California.
National Forests: none documented; suspected on the Rogue RiverSiskiyou and Siuslaw forests because of similar habitat or proximity to
known sites. BLM Districts: none documented; suspected on the Coos
Bay District because of similar habitat and proximity to known sites.
Rare and endangered throughout its range, probably undercollected.
Habitat Associations: Forming loose mats on exposed to shaded soil,
rocks, sand, or gravel in dry or moist situations. Reported from trails,
roadsides, picnic areas, playgrounds, and rock outcrops from sea level to
about 1600 feet elevation, within 10 miles of the coast (Stark 1980;
Shevock and Toren 2001; Norris and Shevock 2004a, 2004b). Plant
associations range from Pinus contorta var. contorta, Picea sitchensis,
Sequoia sempervirens, and grassland at the north end of its range to
dense chaparral on north-facing slopes at the southern end of its range
(Stark 1980). Reported with Bucklandiella heterosticha (= Racomitrium
heterostichum) and Cladonia.
Threats: Triquetrella californica is threatened by commercial, residential,
and recreational development, including facilities on public lands. Most
known historic sites in southern California have been lost to
development (Shevock 2004). The best opportunity for conservation
would be on federal land and in state parks where natural area
management is possible. Some populations appear to exist in disturbed
areas, and seem to be able to coexist with moderate recreational traffic.
Conservation Considerations: Revisit all known localities and monitor
the status of populations. Search for new populations on federal and
state lands. Surveys in suitable habitat and protection of known sites
should be a priority.
Conservation rankings: Global: G1; National: N1. Oregon: S1, List 1;
California: S1. Not known from Washington.
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Preparer: John A. Christy
Date Completed: September 2006. Revised May 2007 with edits from Rob Huff,
Russ Holmes, and Daphne Stone.
Revised by Candace Fallon, February 2011
(Revision only adds Attachment 1, Photos)
ATTACHMENTS:
(1)
Photos
References
Casas, C., R.M. Cros & J. Muñoz. 1993. Triquetrella arapilensis y
especies afines: su morfología y distribución geográphica. Bryologist
96: 122-131.
Christy, J.A. & D.H. Wagner. 1996. Guide for the identification of rare,
threatened or sensitive bryophytes in the range of the northern
spotted owl, western Washington, western Oregon and northwestern
California. USDI Bureau of Land Management, Oregon-Washington
State Office, Portland. 222 pp.
Game, J. 2004. Triquetrella californica. Images of California bryophytes.
https://www.csun.edu/~hcbio028/
Grout, A.J. 1928-1941. Moss Flora of North America North of Mexico. 3
vols. Published by the author. Newfane, Vermont.
Norris, D.H. & J.R. Shevock. 2004a. Contributions toward a bryoflora of
California: I. A specimen-based catalogue of mosses. Madroño 51: 1131.
_______ & _______. 2004b. Contributions toward a bryoflora of California:
II. A key to the mosses. Madroño 51: 133-269.
Oregon Natural Heritage Information Center. 2007. Rare, threatened and
endangered species of Oregon. Oregon Natural Heritage Information
Center, Oregon State University. Portland. 100 pp.
http://oregonstate.edu/ornhic/2007_t&e_book.pdf
Shevock, J.R. 2004. Personal communication with John Christy.
_______ & D. Toren. 2001. A catalog of mosses for the city and county of
San Francisco, California. Madroño 48: 1-16.
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Stark, L.R. 1980. Triquetrella in North America. Bryologist 83: 363-364.
Zander, R.H. 1980. Acid-base color reactions: the status of Triquetrella
ferruginea, Barbula inaequalifolia and B. calcarea. Bryologist 83: 228-233.
_______. 2002. Triquetrella. Version 1. Bryophyte Flora of North America,
Provisional Publication, Missouri Botanical Garden.
http://www.mobot.org/plantscience/bfna/v1/PottTriquetrella.htm
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Attachment 1 – Photos
All photos by J. Harpel, under contract with the Oregon/Washington Bureau of Land
Management.
Alar and basal cells
Upper medial cells
Leaf cross section (1)
Leaf cross section (2)
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Leaf
Leaf apex
Stem cross section
Wet individual
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Whole mount dry
Whole mount wet
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