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Montana Field Guides

Fragile Leaf Dicranum Moss - Dicranum fragilifolium

Potential Species of Concern
Native Species

Global Rank: G4G5
State Rank: SH

Agency Status
MNPS Threat Rank:

External Links

General Description
Plants: Acrocarpous (Vitt 1988), the tufts dense, shiny pale green to ochre. Stems heavily tomentose with deep brown or reddish rhizoids (FNA 2007).

Leaves: Upright-spreading, straight, firm, smooth, lying flat against the stem when dry, (5-)6-7(-7.5) mm long, 0.4-0.6 mm wide, concave below, becoming grooved above, the base lance-shaped, the fragile leaf tips deciduous and usually missing; costa 1/4-1/3 of leaf width at the base, extending beyond leaf tip to form a needle-like point, the outer surface smooth or a little rough, lacking ridges; margins smooth to finely toothed distally (FNA 2007).

Leaf Cells: Smooth, thick-walled (Lawton 1977), weakly bulging between laminal cells; alar region mostly 1-layered, occasionally 2-layered, well-defined, sometimes reaching the costa; costa with 1 line of guide cells; proximal laminal cells long and narrowly-rectangular, the walls usually pitted, sometimes faintly so (FNA 2007); median and distal laminal cells quadrate to short-rectangular and rounded, or erratically angled (Lawton 1971).

Capsules ripen in summer (FNA 2007).

Diagnostic Characteristics
Broken leaf tips lend a distinctive appearance to both Dicranum fragilifolium and D. tauricum, another species with fragile leaves, causing confusion where their ranges overlap. The capsules of D. fragilifolium are usually bowed; those of D. tauricum are straight. In sterile plants, check the X-section of the costa in the proximal half of the leaf. In D. fragilifolium, stereid cells occur in two narrow bands; there are none in D. tauricum (FNA 2007).

Species Range

Range Comments
Greenland; Canada: AB, BC, MB, NL, NT, ON, QC, SK, YT; USA: AK, MI; Europe; Asia (FNA 2007). Known in Montana from Flathead County (Elliott 2016).

Observations in Montana Natural Heritage Program Database
Number of Observations: 5

(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)

Rotten wood and tree bases (Elliott 2016).

Reproductive Characteristics
Dioicous; female plants wider than male plants, and similar in height. Seta ochre-brown, single, 15-25 mm. Capsule ochre, 1.8-2 mm, nearly upright, bowed or sometimes almost straight, rarely produced (FNA 2007).

It is thought that new plants are produced when the broken leaf tips are replaced (FNA 2007).

  • 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. 2007. Flora of North America North of Mexico. Volume 27. Bryophytes: Mosses, Part 1. Oxford University Press, Inc., NY. xxi + 713 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.
    • Malcolm, W. M., and Nancy Malcolm. 2000. Mosses and Other Bryophytes: An Illustrated Glossary. Nelson, New Zealand: Micro-Optics Press.
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Citation for data on this website:
Fragile Leaf Dicranum Moss — Dicranum fragilifolium.  Montana Field Guide.  .  Retrieved on , from