SPECIES FACT SHEET Common Name: Platyhypnidium moss Scientific Name: Platyhypnidium riparioides Recent synonym: Eurhynchium riparioides, Rhynchostegium riparioides Phylum: Bryophyta Class: Bryopsida Order: Hypnales Family: Brachytheciaceae Technical Description: Shoots to 2 mm wide, prostrate, often curved, with a glossy or metallic sheen, green, yellowish-green, brownish-green or copper-colored above, blackening below, 2-15 cm long, irregularly branched. Leaves 1.4-2.5 x 0.8-2 mm, broadly ovate-lanceolate to nearly round, spreading, variously plane, concave, infolded, or loosely twisted near the tip, often oriented somewhat horizontally and giving the shoots a loosely flattened appearance, leaves sometimes lacerated or stripped off by stream scour; costa 1/2 to 3/4 the length of the leaf, sometimes extending nearly to the apex, sometimes forked, often ending in a short spine or tooth at the tip; apex of leaves rounded; margins plane, serrulate nearly to base; median leaf cells long and narrow, 40-100 x 4-5 μm. Capsules uncommon. Distinctive characters: (1) Robust matformer in and along streams, (2) leaves broadly rounded with serrulate margins, (3) metallic green to brownish coppery sheen. Similar species: Hygrohypnum species occur in the same habitat and may have similar orbicular leaves, but never have serrulate margins. Other descriptions and illustrations: Crum 1983: 313; Crum & Anderson 1981: 1072; Lawton 1971: 302; Sharp et al. 1994: 939; Smith 1978: 603. Life History: Details for this species are not documented. The protonema is inconspicuous, forming buds and shoots in the usual fashion of moss growth and development. Capsules are uncommon, but fruiting in summer and fall. Most bryophytes in splash zone habitats are limited to vegetative reproduction, but tend to occur in large monotypic mats that produce many viable fragments for regeneration. Range, Distribution, and Abundance: Widespread in Northern Hemisphere, circumboreal and south to North Africa and northern South America. In the Pacific Northwest, British Columbia south to California, east to Montana. 1
Documented on: National Forests: Columbia River Gorge NSA, Siuslaw. BLM Districts: Coos Bay, Eugene. Widespread but uncommon, probably undercollected. Habitat Associations: Aquatic to emergent, forming mats on rocks, wood, or roots of trees in streams or in spray zone of streams and waterfalls. Partial to full shade. Elevation sea level to about 3000 feet. Forest types include Pseudotsuga menziesii, Tsuga heterophylla, and Picea sitchensis associations. Threats: Road construction, recreational climbing in streambeds (canyoning or canyoneering) and upstream activities such as logging, road construction, and dredging that cause excessive siltation could be detrimental. Water diversion would probably decimate populations. It is unlikely that grazing has much effect other than possible siltation problems. Conservation Considerations: Because Platyhypnidium riparioides is attached to rocks and other substrates in stream beds, riparian buffers alone may not adequately protect populations because of sediment transport within stream channels. Wagner (1997) reported several populations of Platyhypnidium in stream channels on the Eugene BLM District, but Goldenberg (2004) could not relocate some of these and suspected that siltation from nearby logging on private land had buried them. Control of silt-causing activity upstream may be the only way to protect this species, and may not be possible where private lands are interspersed with public lands. Preparer: John A. Christy Date Completed: May 2006 Updated by Camille Duncan in February 2010 (Update added Attachment 1: Photos, to the Species Fact Sheet.) ATTACHMENTS: (1) Photos 2
References Crum, H. 1983. Mosses of the Great Lakes Forest. 3rd edition. University of Michigan Herbarium, Ann Arbor. 417 pp. & L.E. Anderson. 1981. Mosses of Eastern North America. 2 volumes. Columbia University Press, New York. 1328 pp. Goldenberg, D. 2004. Sighting form for Platyhypnidium riparioides, Wolf Creek tributary. Eugene District, Bureau of Land Management. Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical Laboratory, Nichinan, Japan. 362 pp. Montana Natural Heritage Program. 2003. Plant species of concern. Resource Information System, Montana State Library. http:// nhp.nris.state.mt.us/plants/reports/2003_psoc_list.pdf Oregon Natural Heritage Information Center. 2004. Rare, threatened and endangered species of Oregon. Oregon Natural Heritage Information Center, Oregon State University. Portland. 104 pp. http://oregonstate.edu/ornhic/2004_t&e_book.pdf Sharp, A.J., H. Crum & P.M. Eckel (eds). 1994. The Moss Flora of Mexico. 2 volumes. Memoirs of the New York Botanical Garden 69: 1-1113. Smith, A.J.E. 1978. The Moss Flora of Britain and Ireland. Cambridge University Press, Cambridge. 706 pp. Wagner, D.H. 1997. Inventory of bryophytes of Wolf Creek Watershed, Eugene District, Bureau of Land Management, Lane County, Oregon. Report to Eugene BLM District. Northwest Botanical Institute, Eugene. 38 pp + appendices. Washington Natural Heritage Program. 2005. Working list of rare mosses. http://www.dnr.wa.gov/nhp/refdesk/lists/ mosses.html 3
Attachment 1: Photos All photos by Dr. Judy Harpel, under contract with the Oregon/Washington Bureau of Land Management Whole mount dry Whole mount wet 4
Whole mount with sporophyte Sporophyte close-up Stem leaf Branch leaf 5
Stem leaf apex Branch leaf apex 6
Stem leaf alar and basal cells Branch leaf alar and basal cells 7
Stem leaf upper medial cells Branch leaf upper medial cells 8