Common Name: Blister ribbon; narrow mushroom-headed liverwort (Edwards 2003)
Scientific Name: Preissia quadrata (Scop.) Nees
Division: Marchantiophyta (incorrectly called Hepatophyta in U.S. government taxon databases (e.g., ITIS 2008); see Stotler and Crandall-Stotler 2008)
Technical Description: "Thalli medium to large, 3–6 mm wide; dull grayish-green with pores visible to the naked eye as white dots, giving the surface a rough appearance; lateral margins becoming purplish or bleached out in older plants. Pores in microscopic view with cross shaped opening formed by the superimposed rings of cells; barrel-shaped in transverse section. Ventral scales blackish-purple, metallic in appearance, lacking oil-cells.
"Dioicous. Antheridial receptacle stalked, convex across upper surface. Female carpocephala stalked, with 3–5 lobes or rays; pseudoperianths present, enclosing capsules." (Godfrey 1977)
Distinctive Characters: The cells surrounding the pores are whitish, lacking chloroplasts, and form mounds that look like little blisters. Dried herbarium specimens are notably white dotted from the appearance of the cells around the pores. Fresh plants have a peculiar odor that most people find unpleasant, and a hot taste that burns the tongue (Paton 1999). This hot taste may be lacking in regional material (M. Hutten, pers. comm.).
Similar species: Only Marchantia shares the compound, barrel shaped pores of Preissia. The pores in Marchantia may be blister like as in Preissia. Marchantia , the more common genus, usually has gemmae cups on the surface of its thallus; its sexual structures differ conspicuously. Marchantia and Conocephalum (another common, large marchantioid liverwort) both smell sweet compared to Preissia. Absence of oil cells in ventral scales separates Preissia from all other genera with epidermal pores (Paton 1999).
Life History: This species is perennial, visible whenever the substrate is exposed. Plants are best identifiable when fertile, toward the end of the growing season. Most perennial liverworts have an active growing season that matches the rainy season of low elevations: October through May. Plants of high elevations where snow lies late, generally above 5000'/1500 m, may have a short season that coincides with late summer and fall.
Range, Distribution, and Abundance: Circumboreal in temperate to boreal regions. In western North America extending south to California (Doyle and Stotler 2006).
Oregon Natural Heritage Information Center lists Oregon occurrences in Baker, Multnomah, and Wallowa Counties.
Hutten et al. (2005) list a single, site unspecified locality for the Olympic Peninsula. Hong (1980) has no records for the North Cascades of Washington. Fulford (1936) reports a collection from Clallam County, Washington.
BLM: Suspected in Burns, Prineville, Salem and Vale (Oregon) Districts.
USFS: In Oregon documented in Columbia River Gorge National Scenic Area and Wallowa-Whitman National Forest. Suspected in Malheur, Mt. Hood and Umatilla National Forests in Oregon.
Habitat Associations: Grows on soil with little organic material, typically on ledges on cliffs or in crevices in rocky areas. Elevations in Oregon vary widely for this species, from relatively low (Columbia River Gorge) to high (Elkhorn Mountain). Generally strictly calciphilous (Schuster 1992).
"Damp soil and rocks of shaded creek banks and seepages; splash of creeks and cascades; often under willow; places that remain damp for long periods of time following snow-melt." (Doyle and Stotler 2006)
Threats: Most likely threats are development of recreational facilities such as trails or campgrounds in areas where the plants are found.
Conservation Considerations: Precisely map known sites and monitor to evaluate stability of the populations. Whenever ground disturbing actions take place in montane habitats, consider carefully ground searching habitats and re-routing or modifying proposed actions to reduce or eliminate potential negative impacts.
Conservation Rankings and Status:
Global: G5; Oregon: S2
ORNHIC List 3
Washington: Not ranked
BLM/USFS Strategic Species in Oregon
Other pertinent information:
Surveys and Survey Protocol: Conduct extensive search of "rock walls and cliff faces in humid habitats near waterfalls, streams, and lakes at low and subalpine elevations." (Godfrey 1977).
Key to Identification of the Species: Christy and Wagner 1996; Doyle and Stotler 2006.
Preparer: David H. Wagner
Edited by: Rob Huff
Date Completed: October, 2008
Updated in May 2009 by Candace Fallon (Update added Attachment 1, Photos, to the Species Fact Sheet).
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.
Doyle, W. T. & R.E. Stotler. 2006. Contributions toward a bryoflora of
California III. Keys and annotated species catalogue for liverworts and
hornworts. Madroño 53: 89-197.
Edwards, S.R. 2003. English Names for British Bryophytes. Third Edition.
British Bryological Society Special Volume No. 5.
Fulford, M. 1936. Some Hepaticae from Washington, Oregon and Idaho
collected by Dr. Arthur Svihla. The Bryologist 39: 105-111.
Godfrey, J.D. 1977. The Hepaticae and Anthocerotae of Southwestern British
Columbia. Unpublished Ph.D. dissertation on file at the library,
University of British Columbia, Vancouver, B.C., Canada.
Hong. W.S. 1980. Hepaticae of the North Cascades Range, Washington. The
Bryologist 83: 94–102.
Hutten, M, A. Woodward, and K. Hutten. 2005. Inventory of the Mosses,
Liverworts, Hornworts, and Lichens of Olympic National Park,
Washington: Species List. U.S. Geological Survey, Scientific
Investigations Report 2005-5240.
ITIS. 2008. Integrated Taxonomic Information System (official government
database of scientific names) http://www.itis.gov/index.html Accessed
Oregon Natural Heritage Information Center. 2007. Rare, threatened and
endangered species of Oregon. Oregon Natural Heritage Information
Center, Oregon State University. Portland. 100 pp.
Paton, J.A. 1999. The liverwort flora of the British Isles. Harley Books,
Colchester, U.K. 626 pp.
Schuster, R.M. 1992. The Hepaticae and Anthocerotae of North America.
Volume 6. Field Museum of Natural History, Chicago.
Stotler, R.E. and B. Crandall-Stotler. 2008. Correct author citations for some
upper rank names of liverworts (Marchantiophyta). Taxon 57: 289-292.
Attachment 1 – Photos
All photos by Dr. David Wagner, under contract with the Oregon/Washington Bureau of Land Management.
SEM spore proximal
SEM spore side
SEM spore distal
Thallus cross section
Pore from above
Pore from below