SPECIES FACT SHEET
Common Name: Common scissorleaf, red prongwort (Edwards 2003)
Scientific Name: Herbertus aduncus (Dicks.) S.F. Gray
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: Herbertaceae
Taxonomic Note: This species has been treated under a number of different
names, some of them synonyms and some misapplied names of other species.
According to Schofield (2007) the taxon present in our area is subsp. aduncus,
endemic to Pacific North America.
Technical Description: "Plants brownish to red-brown, sometimes dark green
or wine-red, in polsters or turfs. Stems erect to recling, sometimes unbranched
or irregularly few-branched but sometimes with numerous flagelliferous
branches, main stems 1--10 cm. Leaves asymmetrically or symmetrically 2lobed with lobes narrow, 4--7 times as long as wide, vitta strong, extending to
middle of leaf or beyond, of elongate cells, leaves imbricate to second postically,
occasionally somewhat squarrose. Sexual condition dioicous; androecia
intercalary, perigonial leaves less deeply lobed than most leaves, not falcate;
gynoecia terminal, with innovations becoming lateral with continued growth;
perianth ovate, narrowed to mouth, divided into six lanceolate lobes." (Schofield
2007)
Distinctive characters: The three rows of bifid leaves make this genus
unmistakable among liverworts; the slender lobes make it more likely to be
taken for a moss.
Similar species: Only one other species of the genus in the region, H. dicranus.
This species is slightly smaller than H. dicranus; has more deeply divided
leaves (greater than 0.7) which are parallel sided to the base; and has
underleaves which are little different from the lateral leaves.
Life History: Studies of life history traits in this species have not been located.
This species is perennial, visible whenever the substrate is exposed. The plants
are quite brittle and dispersal is probably mainly by fragmentation.
Sporophytes have been found only on plants growing epiphytically, appearing
in late spring to summer (Schofield 2002).
Range, Distribution, and Abundance: Endemic to Pacific coastal area of
North America, this species is fairly abundant from Washington through
British Columbia to Alaska. It is very rare in Oregon, where it reaches the
southern extent of its range. In Oregon it is known only from Saddle Mountain
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in Clatsop County and in the Columbia River Gorge in Multnomah County. In
Washington it occurs along the western coastal strip of the Olympic Peninsula
and at lower elevations in the Cascade Mountains. Schofield (1968) mentions a
collection from Snohomish County. Twelve sites are reported from the Olympic
Peninsula (Hutten, et al. 2005).
ORNHIC listed in Clatsop and Multnomah Counties.
BLM: Suspected in Salem District.
USFS: In Oregon, documented in Columbia River Gorge National Scenic
Area and Mt. Hood National Forest. Suspected in Siuslaw and Willamette
National Forests. In Washington documented from Olympic and Mt.
Baker-Snoqualmie National Forests; suspected on Gifford Pinchot,
Okanogan, and Wenatchee National Forests.
Habitat Associations: Although often an epiphyte in the northern part of its
range, this species is found only on cliffs in Oregon. Its primary associates are
mosses and other liverworts. It is found in cool, moist sites in a variety of forest
types.
Threats: Possible threats are trail building and overcollecting. Sites where
Herbertus aduncus is found in state parks or other similarly protected areas
threats can be presumed to be minimally threatened so long as the land
managers are aware of the presence of the plants.
Conservation Considerations: See Conservation Assessment (Fredericks and
Davis 2005a).
Conservation Rankings and Status:
Global: G5; Oregon: S1
ORNHIC List 2
Washington: Not ranked
BLM/USFS Sensitive Species in Oregon
Other pertinent information:
Surveys and Survey Protocol: Search protected cliffs in the Columbia River
Gorge and on mountain tops in the northern Coast Range, cliffs in the Cascade
Mountains of Oregon and Washington, and trees in moist areas of the Olympic
Peninsula.
Key to Identification of the Species: Schofield 2007; Doyle and Stotler 2006;
Christy and Wagner 1996.
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Preparer: David H. Wagner
Edited by: Rob Huff
Date Completed: January, 2009
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.
Edwards, S.R. 2003. English Names for British Bryophytes. Third Edition.
British Bryological Society Special Volume No. 5.
Fredricks, N. and J. Davis. 2005a. Conservation Assessment for common
scissorleaf Herbertus aduncus (Dicks.) S.F. Gray. Unpublished report prepared
for USDA Forest Service Region 6 and USDI Bureau of Land Management,
Oregon and Washington.
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 20055240.
Oregon Natural Heritage Information Center. 2007. Rare, threatened and
endangered species of Oregon. Oregon Natural Heritage Information Center,
Oregon State University. Portland.
http://oregonstate.edu/ornhic/2007_t&e_book.pdf
Schofield, W.B. 1968. Bryophytes of British Columbia II Hepatics of particular
interest. Journal of the Hattori Bot. Lab. 31: 265-282.
Schofield, W. 2002. Field Guide to Liverwort Genera of Pacific North America.
University of Washington Press, Seattle, Washington, U.S.A.
Schofield, W.B. 2007. Herbertaceae. Bryophyte Flora of North America,
Provisional Publication, Missouri Botnical Garden.
http://www.mobot.org/plantscience/bfna/V3/HerbHerbertaceae.htm
Accessed March, 2008.
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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.
Habit
Leaf
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Oil-bodies in leaf base
Oil-bodies in vitta
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