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A Marsh Moss - Straminergon stramineum
Other Names:  Calliergon stramineum

Native Species

Global Rank: G5
State Rank: SNR

Agency Status
MNPS Threat Rank:

External Links

General Description
Plants: Pleurocarpous (Vitt 1988). Growing in uncrowded, clumps or interwoven mats (Lawton 1971), pale green with white or yellow tones (FNA 2014) or somewhat straw-colored (Crum & Anderson et al. 1981). Stems 5-10 cm in length or longer (Lawton 1971), unbranched (Vitt 1988) to few-branched; possessing a central strand and without a hyalodermis; exterior pseudoparaphyllia wide, deltoid to variously shaped; rhizoids stemming from diverse spots on leaves or forming rows on the stem; axillary hairs scarce, with 1 or 2 transparent distal cells (FNA 2014).

Leaves: Stem leaves dense and overlapping, or occasionally lax and spreading when moist, sometimes a little curved and twisted when dry, 1-2 mm in length, 0.4-1 mm in width (Lawton 1971), egg-shaped or slenderly so, cupped, not pleated longitudinally; margins smooth (FNA 2014) and flat (Lawton 1971); base slenderly extending down the stem; leaf tip area often hood-shaped (FNA 2014); costa ca 3/4 of the leaf length. Branch leaves smaller and resembling the stem leaves (Lawton 1971).

Leaf Cells: Alar cells square or lengthened a little to a lot, transparent and darkening to brown, swollen, the alar region well-defined and egg-shaped, sometimes widely so; medial laminal cells fine- to more thickly-walled, sometimes pitted (FNA 2014), long and narrow above, becoming shorter below (Crum & Anderson et al. 1981); apical cells including a group of a few wide, transparent cells immediately proximal of the apex (Lawton 1971).

Diagnostic Characteristics
Rhizoids are frequently produced near the leaf tips, producing brown “tufts” (FNA 2014).

Calliergon cordifolium resembles Calliergon stramineum but has a somewhat deltoid and wide alar region with imprecise boundaries. The alar region of C. stramineum is egg-shaped and the boundaries are sharply defined (FNA 2014).

Species Range

Range Comments
North American Range

AK to NL and NS, WA to MT, s to CA and NM, also WI, MI se to VA, from there n and ne to VT and NH (FNA 2014). Known in Montana from Beaverhead, Flathead, Lincoln, Ravalli, Sanders, and Stillwater Counties (Elliott 2016).

Observations in Montana Natural Heritage Program Database
Number of Observations: 29

(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)

Low-nutrient and low- to high-mineral content (FNA 2014) wetlands, often intermixed with Sphagnum (Elliott 2016), lake shores; typically montane. Elevation to ca 9840 feet (Lawton 1971).

Reproductive Characteristics
Dioicous. Interior perichaetial bracts pleated longitudinally (FNA 2014). Seta 3-5 cm tall (Lawton 1971), yellow with red tones (Crum & Anderson et al. 1981). Theca 1.5-2.5 mm in length (Lawton 1971), bowed, the neck narrowing (Crum & Anderson et al 1981). Exostome with an external network of lines below and toothed above (FNA 2014), the processes with narrow openings and 1 or 2 short cilia (Crum & Anderson et al. 1981).

  • 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
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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.
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A Marsh Moss — Straminergon stramineum.  Montana Field Guide.  .  Retrieved on , from