Search Field Guide
Advanced Search
MT Gov Logo
Montana Field Guide

Montana Field Guides

A Mat Moss - Brachytheciastrum collinum
Other Names:  Brachythecium collinum

Native Species

Global Rank: G5
State Rank: SNR

Agency Status


External Links

General Description
Plants: Pleurocarpous (Vitt 1988). Growing in open to compact tufts, usually transforming from green when young to light yellow or ochre with maturity (FNA 2014), frequently shiny (Lawton 1971); rhizoids typically numerous (Flowers 1973). Stems prostrate to upwardly inclined, or upright in compact clumps, catkin-like (with crowded, overlapping leaves), round in X-section, 2-4 cm in length (FNA 2014), branching unevenly (Lawton 1971); possessing a central strand. Branches to 4 mm, round in X-section (FNA 2014).

Stem Leaves: Flat against the stem below, overlapping strongly (FNA 2014) or spreading a little when moist (Flowers 1973), 0.5-1.5 mm in length, 0.2-0.7 mm in width, egg-shaped or approaching broadly lance-shaped, straight to curved like a sickle, seldom folded longitudinally (FNA 2014), cupped; base decurrent (Lawton 1971); margins roughly saw-toothed nearly to the bottom, flat or curved back and down below; apex usually suddenly (seldom slowly) forming a short and spreading acumen, frequently all apices on the stem pointing in the same direction; costa ca 1/2 or more the length of the leaf, sometimes nearly lacking, terminal spine lacking (FNA 2014).

Branch Leaves: Smaller and a little more slender than the stem leaves (FNA 2014), 0.8 mm in length, 0.4 mm in width, the margins saw-toothed or seldom mostly smooth, the costa occasionally with a terminal spine (Lawton 1971).

Leaf Cells: Alar cells somewhat chlorophyllous (Flowers 1973), nearly square, the alar area small and well-demarcated; laminal cells long and narrow, the basal cells similar (FNA 2014).

Diagnostic Characteristics
Plants growing in dry, open habitats are frequently yellow-brown with green around the edges. In moist, shaded habitats, they may be large and brilliant green (Flowers 1973).

Range Comments
North American Range

Canada: YT, BC to SK; USA: western half (ND s to TX, w to the coastal states); Mexico (Baja California and Chihuahua) (FNA 2014). Known in Montana from Carter, Cascade, Custer, Fallon, Flathead, Gallatin, Granite, Lake, Lewis and Clark, Lincoln, Madison, McCone, Mineral, Park, Powder River, Ravalli, and Valley Counties (Elliott 2016).

Observations in Montana Natural Heritage Program Database
Number of Observations: 83

(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)

Humus, rotting logs (Flowers 1973), soil and soil over rock (Elliott 2016); from dry to moist and open to somewhat canopied areas. Elevation: 0-12,140 feet (FNA 2014).

Reproductive Characteristics
Seta somewhat reddish, 6-14 mm tall, papillae-roughened throughout or sometimes in the bottom quarter. Capsule orangish, 1-1.8 mm in length, ascending somewhat to level; cilia similar in length to that of the endostome segments (FNA 2014).

  • Literature Cited AboveLegend:   View Online Publication
    • 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.
    • Flowers, S. 1973. Mosses: Utah and the West. Brigham Young University, Provo, Utah. 567 p.
    • Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical Laboratory. Japan: Yamabuki-cho, Shinjuku-ku, Tokyo. 362 pages plus appendices.
    • Vitt, D. J. Marsh, and R. Bovey. 1988. Mosses, Lichens & Ferns of Northwest North America. Seattle, WA: University of Washington Press. 296 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Elliot, J. C. 1993. Second checklist of Montana mosses. Unpublished report. U.S. Forest Service, Region 1. Missoula, MT. 45 pp.
    • 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.
  • Web Search Engines for Articles on "A Mat Moss"
Login Logout
Citation for data on this website:
A Mat Moss — Brachytheciastrum collinum.  Montana Field Guide.  .  Retrieved on , from