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Alpine Bryum Moss - Imbribryum alpinum
Other Names:  Bryum alpinum

Status Under Review
Native Species

Global Rank: G4G5
State Rank: SNR

Agency Status
MNPS Threat Rank:

External Links

General Description
Plants: Acrocarpous (Vitt 1988). Growing in crowded, erect clumps (Lawton 1971). Deep red to green with red tones, seldom green throughout, occasionally becoming black with time (FNA 2014). Stems 2-5 cm tall, occasionally forked (Lawton 1971), shiny, catkin-like, mature stems occasionally crowded with rhizoids (FNA 2014).

Leaves: Barely contorted (Crum & Anderson et al. 1981) and closely overlapping when dry (FNA 2014), upright or spreading a little when wet (Crum & Anderson et al. 1981), 0.5-0.8 mm in width (Lawton 1981), 1-3 mm in length, widely lance-shaped or slender and egg- or tongue-shaped, slightly cupped, acute apically, the base not extending down the stem; margins flat and smooth to finely saw-toothed above, tightly rolled back and downwards below, without a border; costa reddish, extending to just below the apex to a little beyond, forming a strong awn (FNA 2014).

Leaf Cells: Alar cells not distinguished; basal laminal cells forming 1 row, occasionally colored; proximal laminal cells suddenly nearly square to short quadrangular, 1-3:1, not as long as the cells above; middle and upper cells thick-walled, worm-shaped or long, narrow, and 6-sided, 6-8:1; margins of 1 cell layer (FNA 2014), the cells slightly longer but not forming a distinct border (Lawton 1971).

Fruits ripen in springtime and summertime (FNA 2014).

Diagnostic Characteristics
Hard to identify because of morphological variability. Most collections from the western USA have widely ovate leaves rather than narrow ones, and upper laminal cells that are less elongate (FNA 2014).

B. alpinum has narrower leaves and leaf tips, more tightly rolled margins, and longer, narrower cells than the similar Bryum muehlenbeckii.

Range Comments
North American Range

An uncommon boreal-temperate species. Canada: NL; USA: AK, jumping s to CA, CO and IL (FNA 2014). Known in Montana from Beaverhead, Cascade, Flathead, and Glacier Counties (Elliott 2016).

Wet acidic rocks or in soil overlying them. Elevation: 0-8200 feet (FNA 2014).

Reproductive Characteristics
Dioicous. Seldom producing fruit. Seta 1-3 cm tall, deep red (Crum & Anderson et al. 1981) to somewhat brown or purple. Capsule pear-shaped, 3-5 mm in length, purplish with red tones, ascending to drooping; peristome double; cilia long and transversely ridged (FNA 2014) to knobby (Lawton 1971).

Specialized vegetative reproduction by rust-colored tubers growing on axillary rhizoids, rare (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.
    • 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?
    • 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.
    • Smith, A.J.E. 1980. The Moss Flora of Britain and Ireland. Cambridge University Press, Cambridge. 705 pp.
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Citation for data on this website:
Alpine Bryum Moss — Imbribryum alpinum.  Montana Field Guide.  .  Retrieved on , from