SPECIES FACT SHEET
Common Name: Racomitrium moss
Scientific Name: Codriophorus depressus
Recent synonyms: Racomitrium depressum; on the BLM Oregon list
under this name
Division: Bryophyta
Class: Bryopsida
Order: Grimmiales
Family: Grimmiaceae
Taxonomic Note: Codriophorus depressus has long been confused with
a number of other species of Codriophorus (formerly Racomitrium) and
has been treated most recently by Bednarek-Ochrya and Ochyra (2006).
Lawton (1971) included C. depressus in a broader concept of
Racomitrium.heterostichum but Frisvoll (1988) resurrected the concept of
Racomitrium depressum that was originally named from California
material in 1868. It has not yet been found in British Columbia and
Washington, and early reports of the species from these areas (Frye
1917, Jones 1933) are presumably errors and must be referred to other
species.
Technical Description: Plants olive green, brownish to nearly black, 410 (13) cm long, simple or branched. Leaves concave, erect, unistratose,
usually 3-4 x 1-1.5 mm, loosely imbricate when dry, apex acute to
obtuse, margins mostly entire or with a few blunt teeth at the apex,
recurved 2/3-3/4 the length of the leaf on one or both sides. Leaf cells
smooth or faintly papillose, alar cells not differentiated. Costa on back
(abaxial) side of leaf broad and flattened, 1-1.5 mm wide at base,
reaching leaf apex but not prolonged as an awn. Seta twisted clockwise.
Peristome teeth smooth or nearly so. Distinctive characters: (1) Shoots
robust, to 10 cm long, (2) leaves large, to 4 x 1.5 mm, (3) costa flat and
very broad, to 1.5 mm wide at base, (3) leaves without awns, (4) leaf cells
smooth, (5) leaf margins often recurved on both sides, (6) alar cells not
differentiated. Similar species: Codriophorus acicularis (= Racomitrium
aciculare) has (1) leaves broadly rounded (lingulate) and coarsely toothed
at the apex, (2) leaf cells distinctly papillose over the centers of the cells,
and (3) the costa narrow and rounded at back of the leaf. Codriophorus
norrisii (= Racomitrium norrisii) is similar to C. acicularis except that it is
(1) smaller, (2) has smaller papillae over the cell walls instead of the
centers of the cells, and (3) its leaves have thickend margins (limbidia) of
two layers of cells (bistratose). Bucklandiella pacifica (= Racomitrium
pacificum) has (1) the costa narrow and rounded at the back of the leaf,
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(2) grows in upland habitats not associated with streams, and (3) is
restricted to low elevations west of the Cascade-Sierra axis. Other
descriptions and illustrations: Frye 1917: pl. 23; Jones 1933: 53;
Frisvoll 1988: 106; Bednarek-Ochrya and Ochyra (2006).
Life History: Details for Codriophorus depressus are not documented.
The protonema is inconspicuous, forming buds and shoots in the usual
fashion of moss growth and development. Capsules develop in the
summer and fall. Plants are subject to scour at high water, evidenced by
silt and eroded leaves (Frisvoll 1988).
Range, Distribution, and Abundance: Endemic to western North
America. Known only from the Sierra Mountains of California and
Nevada, and the southern Cascade and Klamath mountains of
southwestern Oregon and northwestern California. Its range is somewhat
uncertain because of longtime confusion with other species of
Bucklandiella and Codriophorus (all formerly Racomitrium). In Oregon, it
occurs in the southern Cascade Range and Klamath Mountains.
Specimens reported from British Columbia, Washington (Frye 1917,
Jones 1933), and Quebec must be referred to other species.
National Forests: none documented; suspected on Rogue River-Siskiyou,
Fremont-Winema, and Umpqua NFs. BLM Districts: documented on
Medford District; suspected on Coos Bay and Roseburg districts.
Rare, probably undercollected.
Habitat Associations: Forming mats on rocks in perennial or
intermittent streams, and in the spray zone of waterfalls, between 400
and 11,000 feet elevation. Habitats are subject to scour at high water.
Bednarek-Ochrya and Ochyra (2006) stress its occurrence in intermittent
streams and other seasonally wet habitats that dry out by midsummer.
However, their emphasis on its occurrence in montane to subalpine
habitats is misleading because it has been documented from as low as
400 feet. Forest types include Pinus ponderosa, Pinus jeffreyi, Quercus
spp., Pseudotsuga menziesii, Tsuga heterophylla, Abies x shastensis,
Abies concolor, and Tsuga mertensiana associations.
Threats: Upstream activities that cause siltation could be detrimental to
Codriophorus depressus. Recreational gold dredging, boating, and
canyoning (canyoneering) can also damage mosses in splash zones by
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abrasion or removal of moss. Presumably, its streamside habitat will
become more and more degraded with ongoing development and
population pressures worldwide.
Conservation Considerations: Because of longtime confusion with other
species of Bucklandiella and Codriophorus (all formerly Racomitrium), the
current distribution and abundance of C. depressus is not well known.
Revisit known sites in Oregon, the northern extent of its range, and
search for new sites before reassessing its conservation status.
Conservation rankings: Global: G2G3; National: NNR. Oregon: S1, List 2;
California: SNR. Not yet known from Washington.
Preparer: John A. Christy
Date Completed: August 2006. Revised May 2007 with edits from Rob Huff, Russ
Holmes, and Daphne Stone.
Revised February 2009 by Rob Huff. (Revision only clarified suspected potential
range in Oregon to include the Fremont-Winema and Umpqua National Forests)
Revised by Candace Fallon, February 2011
(Revision only adds Attachment 1, Photos)
ATTACHMENTS:
(1)
Photos
References
Bednarek-Ochrya, H. & R. Ochyra. 2006. Codriophorus. Version 1.
Bryophyte Flora of North America, provisional publication. Missouri
Botanical Garden.
Frisvoll, A.A. 1988. A taxonomic revision of the Racomitrium
heterostichum group (Bryophyta, Grimmiales) in N. and C. America, N.
Africa, Europe and Asia. Gunneria 59: 1-289.
Frye, T.C. 1917. The Racomitriums of western North America. Bryologist
20: 91-98.
Jones, G.N. 1933. Family Grimmiaceae. Pp. 1-60 in: Grout, A.J. Moss
Flora of North America North of Mexico. Vol. 2. Published by the
author. Newfane, Vermont.
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Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical
Laboratory, Nichinan, Japan. 362 pp.
Norris, D.H. & J.R. Shevock. 2004. Contributions toward a bryoflora of
California: I. A specimen-based catalogue of mosses. Madroño 51: 1131.
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
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Attachment 1 – Photos
All photos by J. Harpel, under contract with the Oregon/Washington Bureau of Land
Management.
Aral and basal cells
Peristome teeth
Upper medial cells
Peristome teeth closeup
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Leaf (1)
Leaf (2)
Leaves
Leaf apex
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Leaf cross section
Wet capsule
Whole mount wet
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