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A Ptychostomum Moss - Ptychostomum pallescens
Other Names:  Bryum pallescens

Native Species

Global Rank: G5
State Rank: SNR

Agency Status
MNPS Threat Rank:

External Links

General Description
Plants: Acrocarpous. Growing in loose to crowded patches of erect shoots (FNA 2014) or forming deep cushions (Lawton 1971), green or green with yellow tones. Stems 1-4 cm (FNA 2014), forked, red (Lawton 1971), with leaves dense at the top of the stem (comose); generally rhizoids present (FNA 2014).

Leaves: Green with yellow or red tones, slightly or greatly twisted and curved when dry, upright or spreading a little when wet, 1-3.5 mm in length (FNA 2014), 0.7-0.9 mm in width, the base red (Lawton 1971), lance-shaped with ovate tendencies, plane to shallowly cupped, acuminate, a little larger higher on the stem; margins rolled tightly back and downward proximally to half or more of the leaf length, the border well-defined; costa extending well beyond the apex, forming an awn, the awn somewhat smooth and colored (FNA 2014).

Leaf Cells: Middle and upper laminal cells diamond-shaped, 3-4:1, the walls fine or slightly thicker (firm), narrower than to as wide as the proximal laminal cells; proximal cells rectangular, 3-4:1; limbidium (border) unistratose, lightly colored to green or yellow (FNA 2014).

Fruit ripens in late spring to summer (FNA 2014).

Diagnostic Characteristics
The comparable Bryum lisae var. cuspidatum is synoicous rather than autoicous and has egg-shaped openings in its endostome segments rather than stretched oval ones (FNA 2014).

Range Comments
North American Range

AK to NL and NS, western states (except unknown in NM), ND, SD, e and ne to ME, dipping s into MO, OH, PA, WV and VA (FNA 2014). Known in Montana from Cascade, Flathead, Glacier, Lake, Lewis and Clark, Madison, Meagher, Missoula, Ravalli, and Teton Counties (Elliott 2016).

Observations in Montana Natural Heritage Program Database
Number of Observations: 12

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Wet to moist rocky soil, such as in stone fissures (Crum & Anderson et al. 1981), springs or on creek banks. Elevation: 0-10,830 feet (FNA 2014).

Reproductive Characteristics
Autoicous. Seta 10-30 mm. Capsule pear-shaped and stretched (FNA 2014), the neck similar in length to the urn (Crum & Anderson et al. 1981), 2-4 mm in length, brown; exostome dentitions yellow below, hyaline above; endostome segments with stretched oval openings, the cilia long, knobby or transversely ridged (FNA 2014).

Specialized vegetative reproduction not present (FNA 2014).

  • Literature Cited AboveLegend:   View Online Publication
    • Crum, H.A. and L.E. Anderson. 1981. Mosses of Eastern North America. 2 volumes. Columbia University Press, New York. 1328 pp.
    • Elliott, J.C. and A.K. Pipp. 2018. A Checklist of Montana Mosses (1880-2018). Updated 3 January, 2020. Montana Natural Heritage Program, Helena, Montana. 73 pp.
    • Flora of North America Editorial Committee, eds. 2014. Flora of North America North of Mexico. Volume 28. Bryophytes: Mosses, Part 2. Oxford University Press, Inc., NY. xxi + 702 pp.
    • Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical Laboratory. Japan: Yamabuki-cho, Shinjuku-ku, Tokyo. 362 pages plus appendices.
  • Additional ReferencesLegend:   View Online Publication
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    • Flowers, S. 1973. Mosses: Utah and the West. Brigham Young University, Provo, Utah. 567 p.
    • Lawton, E. 1971. Keys for the Identification of the Mosses on the Pacific Northwest. Reprinted from 'Moss Flora of the Pacific Northwest'. Published as Supplement No. 2 of the Journal of the Hattori Botanical Laboratory. Nichinan, Miyazaki, Japan. 66 pp.
    • Malcolm, B., N. Malcolm, J. Shevock, and D. Norris. 2009. California Mosses. Nelson, New Zealand: Micro-Optics Press. 430 pp.
    • Smith, A.J.E. 1980. The Moss Flora of Britain and Ireland. Cambridge University Press, Cambridge. 705 pp.
    • Vitt, D. J. Marsh, and R. Bovey. 1988. Mosses, Lichens & Ferns of Northwest North America. Seattle, WA: University of Washington Press. 296 p.
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Citation for data on this website:
A Ptychostomum Moss — Ptychostomum pallescens.  Montana Field Guide.  .  Retrieved on , from