SPECIES FACT SHEET
Common Name: Scorched spadewort, dark earwort (Edwards 2003)
Scientific Name: Scapania obscura (Arn. & Jens.) Schiffn.
Division: Marchantiophyta (incorrectly called Hepatophyta in U.S. government
taxon databases (e.g., ITIS 2008); see Stotler and Crandall-Stotler 2008)
Class: Jungermanniopsida
Order: Jungermanniales
Family: Scapaniaceae
Technical Description: "Plants medium-sized, 2.0–2.5 mm wide, light golden(or brownish-) green to deep, rich reddish-brown, with both brown and red
pigments. Stems the same color as the rest of the plants; in transverse section
the cortical cells golden-brown, smaller in diameter than the hyaline cells of the
medulla, which are ± abruptly larger. Leaves lax, ruffly; margins entire, not
bordered, the marginal cells collenchymatous. Dorsal lobes transversely
inserted, rounded-quadrate to rounded-oblong, extending across and slightly
beyond the stem the length equal to 0.65–0.80 X that of the ventral lobes, apex
blunt to rounded. Ventral lobes little larger than the dorsal, ± ovate, the apex
blunt to rounded, the width 0.6–1.0 X the length. Keel ± straight to weakly
arched, ca. 0.50–0.65 X the length of the ventral lobe. Median cells of leaf ca.
20 X 30–35 µm. Trigones small. Cuticle weakly papillose." (Godfrey 1977)
Gemmae, when present, 2-celled, ovoid. Oil-bodies 2–5 per cell, only slightly
larger than (about 1.5 X) the chloroplasts.
Distinctive Characters: This species has small, dark brown to black shoots
with bilobed leaves that are not very tightly folded. The dorsal lobe is nearly as
large as the ventral lobe; the dorsal lobe is not decurrent and the ventral lobe is
long decurrent. Lobe tips are rounded and spread back from the stem.
Similar species: The loosely folded lobes and dark color makes this look very
much like Gymnocolea inflata. Gymnocolea has minute underleaves which are
inconspicuous but detectable by careful examination, and more equal and less
folded leaves. The most similar Scapania is S. subalpina, a larger plant that
also has subequal lobes. It has a border of thick walled cells and lacks the dark
pigmentation of S. obscura, and sometimes has dentate leaf margins while S.
obscura always has entire margins.
Life History: Published studies of life history traits in this particular species
have not been located. This species is perennial, visible whenever the substrate
is exposed. It is a plant of high elevations where snow lies late, generally above
5000'/1500 m, thus it will have a short season that coincides with late
summer and fall. Sporophytes are unknown (Schuster 1974, Damsholt 2002)
and gemmae were not seen in Oregon material although reported from British
Columbia (Godfrey 1977).
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Range, Distribution, and Abundance: Scattered in northern Europe, Alps and
the Nordic countries, and possibly in eastern Russia (Damsholt 2002); equally
scarce in North America from Greenland and Baffin Island (Schuster 1974) to
the Pacific Northwest.
Listed by Oregon Natural Heritage Information Center in Lane County.
BLM: Suspected in Eugene District.
USFS: Documented in Willamette National Forest. Suspected in Mt. Hood
and Umpqua National Forests.
Habitat Associations: On peaty soil close to streams below cold water springs
and in snow melt seepage channels. It may be submerged much of the year. At
least in this region, it grows in full sun.
Threats: Recreational activities could adversely affect the health of populations
where traffic is heavy.
Conservation Considerations: The Oregon site is very close to a popular
spring in the Three Sisters Wilderness, where there is a clear negative impact
on the population from hikers using the spring as a water source. Consider
diverting trails away from known sites and discouraging camping in the vicinity
of sites.
Conservation Rankings and Status:
Global: G3Q; Oregon: S1
ORNHIC List 3
Washington: Not ranked
BLM/USFS Strategic Species in Oregon
Other pertinent information:
Surveys and Survey Protocol: Search banks of small streams in subalpine
and alpine regions, paying particular attention to reaches below cold water
springs where water level and water temperature is relatively constant. Search
should be combined with search for Chiloscyphus gemmiparus and Marsupella
emarginata aquatica.
Key to Identification of the Species: Christy and Wagner 1996.
Preparer: David H. Wagner
Edited by: Rob Huff
Date Completed: October, 2008
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Updated in May 2009 by Candace Fallon (Update added Attachment 1, Photos,
to the Species Fact Sheet).
ATTACHMENTS:
(1)
Photos
References:
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.
Damsholt, K. 2002. Illustrated Flora of Nordic Liverworts and Hornworts.
Nordic Bryological Society, Lund, Sweden.
Edwards, S.R. 2003. English Names for British Bryophytes. Third Edition.
British Bryological Society Special Volume No. 5.
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.
ITIS. 2008. Integrated Taxonomic Information System (official government
database of scientific names) http://www.itis.gov/index.html Accessed
August 2008.
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
Paton, J.A. 1999. The liverwort flora of the British Isles. Harley Books,
Colchester, U.K. 626 pp.
Schuster, R.M. 1974. The Hepaticae and Anthocerotae of North America.
Volume 3. Columbia University Press, New York.
Stotler, R.E. and B. Crandall-Stotler. 2008. Correct author citations for some
upper rank names of liverworts (Marchantiophyta). Taxon 57: 289-292.
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Attachment 1 – Photos
All photos by Dr. David Wagner, under contract with the Oregon/Washington Bureau of Land
Management
Shoot
Leaf
4
Shoot
Ventral stripped
5
Leaf ventral
Leaf
6