SPECIES FACT SHEET
Common Name: Hummock haircap, Slender haircap, Narrow-leaved
haircap
Scientific Name: Polytrichum strictum
Recent synonyms: Polytrichum juniperinum var. affine
Division: Bryophyta
Class: Bryopsida
Order: Polytrichales
Family: Polytrichichaceae
Technical Description: Plants erect, 1-10 (20) cm tall, mostly
unbranched, stems between the leaves densely covered with whitish to
light brown wooly tomentum. Leaves (2) 4-6 (8) mm long, awl-shaped,
green, bluish-green to reddish brown with reddish-brown tips, stiffly
appressed when dry, erect-spreading when moist, the upper (adaxial)
side of the leaves covered with parallel ranks of tissue (lamellae) 5-8 cells
tall extending from leaf base to apex. Leaf margins entire, membranous,
transparent (hyaline), folded inward and covering the lamellae. Setae
brown, 2-4 (6) cm long. Capsules brown, 2-3 (5) mm long, square in
cross-section. Peristome membranous like the head of a drum, not
composed of teeth. Distinctive characters: Polytrichum strictum is the
only Polytrichum growing on Sphagnum hummocks that has overlapping
leaf margins that hide the lamellae. The overlapping leaf margins can be
seen with a hand lens as a fine line running down the center of the
adaxial leaf surface. Similar species: Polytrichum juniperinum looks very
similar to P. strictum but (1) lacks the whitish wooly tomentum on the
stem and (2) grows only on dry, exposed mineral soil or sand. Polytrichum
commune sometimes grows on Sphagnum hummocks in the Pacific
Northwest but its leaves are toothed and do not have infolded margins,
so the lamellae are plainly visible. Other descriptions and illustrations:
Frye 1910: 325; Frye 1937: 127; Lawton 1971: 42; Crum and Anderson
1981: 1272; Ireland 1982: 683; Vitt et al. 1988: 57; Christy and Wagner
1996: VII-52; Merrill 2007: 139.
Life History: Details for Polytrichum strictum are not documented. The
protonema is inconspicuous, forming buds and shoots in the usual
fashion of moss growth and development.
Range, Distribution, and Abundance: Circumboreal and bipolar. In the
Pacific Northwest, known from British Columbia, Alberta, Montana,
Washington, Oregon, and California (Norris and Shevock 2004).
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National Forests: none documented; suspected on forests in the region
with suitable bog or fen habitat. Documented from Olympic National
Park (Hutten et al. 2005). BLM Districts: none documented; suspected on
the Salem and Coos Bay districts.
Rare in Oregon and Washington but a common component of boreal bogs
and fens. Because Polytrichum strictum is conspicuous, it is unlikely that
it has been overlooked in bogs and fens in the Pacific Northwest if these
habitats have been well inventoried bryologically.
Habitat Associations: Plants scattered individually or forming loose
turfs on organic soils, particularly on top of Sphagnum hummocks, in
coastal and montane bogs and fens. Tops of hummocks receive the most
intense insolation and are the most nutrient-poor sites in these habitats.
Associated species include Vaccinium oxycoccos, Ledum glandulosum,
Carex, the mosses Sphagnum, Pohlia sphagnicola, and Aulacomnium
palustre. Associated vascular plants may be stunted because of poor
nutrient status.
Threats: Over the last century, fen habitats have been impacted by
grazing, water diversion, water impoundment, drainage projects, road
construction, commercial harvest of peat and sphagnum moss, and
succession in the absence of fire. Changes in water regime, nutrient
inputs, and succession lead to the disappearance of fen communities
and species. Federal and state regulations prohibit building new roads in
wetlands, but dust from nearby roads can alter pH in fens and smother
small plants such as bryophytes. Livestock trample and destroy
bryophyte cover. Commercial collecting of peat depletes bryophyte
diversity in fens, although some species require periodic disturbance.
Many peatlands are converting to forest in the absence of fire and few
new peatlands are forming. Scientific collecting can also deplete
populations of rare mosses such as Polytrichum strictum.
Conservation Considerations: Revisit known localities to reconfirm
presence of populations, and conduct searches for new populations. At
known sites or in potential habitat, manage peatlands to maintain
hydrology, peat formation processes, and fen species composition.
Conservation rankings: Global: G4; National: NNR. California: SNR;
Montana: SNR; Oregon: S1, List 2; Washington: S2, Working List.
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Preparer: John A. Christy
Date Completed: June 2007
Updated by: Rob Huff
Date Completed: August 2011
Update removed Eugene BLM as suspected for this species; lack of habitat.
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. 222 pp.
Crum, H. & L.E. Anderson. 1981. Mosses of Eastern North America. 2
volumes. Columbia University Press, New York. 1328 pp.
Frye, T.C. 1910. The Polytrichaceae of western North America.
Proceedings of the Washington Academy of Sciences 12: 271-328.
_______. 1937. Family Polytrichaceae. Pp. 99-128 in: Grout, A.J. Moss
Flora of North America North of Mexico. Volume 1. Published by the
author. Newfane, Vermont.
Hutten, M., A. Woodward & 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. 78 pp.
Ireland, R.R. 1982. Moss Flora of the Maritime Provinces. National
Museum of Natural Sciences, Publications in Botany. 13: 1-738.
National Museum of Natural Sciences, Ottawa.
Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical
Laboratory, Nichinan, Japan. 362 pp.
Merrill, G.L.S. 2007. Polytrichum. Pp. 133-140 in: Flora of North America
Editorial Committee. Flora of North America north of Mexico. Volume
27. Oxford University Press, New York. 713 pp.
Norris, D.H. & J.R. Shevock. 2004a. Contributions toward a bryoflora of
California: I. A specimen-based catalogue of mosses. Madroño 51: 1131.
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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
Vitt, D.H., J.E. Marsh & R.B. Bovey. 1988. Mosses, Lichens & Ferns of
Northwest North America. University of Washington Press, Seattle.
296 pp.
Washington Natural Heritage Program. 2005. Working list of mosses.
Washington Department of Natural Resources, Olympia.
http://www.stage.dnr.wa.gov/nhp/refdesk/lists/mosses.html
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