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Montana Field Guides

A Fern Moss - Hypnum circinale

Native Species

Global Rank: G5
State Rank: SNR

Agency Status
MNPS Threat Rank:

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General Description
Plants: Pleurocarpous (Vitt 1988), typically growing in widely-spreading mats (Lawton 1971), green with grey or gold tones or deep green. Stems typically prostrate, pinnate, sometimes somewhat erratically so, bipinnate, or occasionally erratically branched, usually 3-5 cm, sometimes longer, russet; branches 5-10 mm in length; hyalodermis and central strand both absent; pseudoparaphyllia present, sometimes lance-shaped (FNA 2014); cortical stem cells tiny and with thick walls (Lawton 1971).

Stem Leaves: Curved in sickle-like fashion and pointed in one direction to rolled nearly into a circle at the leaf apex, 1.5-2.2 mm in length, to 0.7 mm in width (FNA 2014), cupped below (Lawton 1971), egg-shaped to lance-shaped and somewhat deltoid, slowly tapering to a long, tapering acumen, the base only faintly extending down the stem and frequently only one side lobed; leaf edges flat or seldom faintly curved back and downward on only one side (FNA 2014), finely saw-toothed above and occasionally on the basal edges (Lawton 1971); costa obscure; branch leaves smaller than stem leaves, to 1.5 mm in length and to 0.4 mm in width, the edges more noticeably saw-toothed (FNA 2014).

Leaf Cells: Laminal cells porose, not papillose; medial laminal cells narrower than the basal cells (FNA 2014), long; basal laminal cells shorter than the medial cells, frequently (Lawton 1971) colored yellow, the walls pitted; alar cells typically pigmented, nearly square to deltoid and somewhat rounded (FNA 2014), a little swollen (Lawton 1971), extending 2-5 cells up along the margin, the region reasonably distinct (FNA 2014).

Sporophytes appear in fall and early winter; spore sacs ripen in winter (FNA 2014).

Range Comments
North American Range

AK, BC and AB, WA to CA, ID and MT (FNA 2014). Known in Montana from Flathead, Glacier, Lake, and Mineral Counties (Elliott and Pipp 2016).

Observations in Montana Natural Heritage Program Database
Number of Observations: 7

(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)

Growing on trunks of trees, rotting logs (FNA 2014), seldom on stone (Lawton 1971), subalpine evergreen woods. Occurring from lowlands to about 4920 feet elevation (FNA 2014).

Reproductive Characteristics
Dioicous with the male and female plants resembling each other, or phyllodiocous with the male plants small and growing on the female plants epiphytically. Exterior perichaetial bracts bent back and downward; interior perichaetial bracts upright with a thin acumen (FNA 2014), to 5 mm in length, sheath-like (Lawton 1971), the edges finely saw-toothed above. Seta 6-20 mm tall, russet, smooth. Capsule 0.8-1.5 mm in length, somewhat red, tilted to level (FNA 2014), barely shrunken below the opening when dry (Lawton 1971); operculum cone-shaped with a short tip; exostome teeth 16, with a zigzag line on the outer face, fine lines or ridges below, and papillae above; endostome processes 16, similar in height as the teeth, keeled, cilia present. Calyptra hairless and draping hood-like (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.
    • 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, B., N. Malcolm, J. Shevock, and D. Norris. 2009. California Mosses. Nelson, New Zealand: Micro-Optics Press. 430 pp.
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Citation for data on this website:
A Fern Moss — Hypnum circinale.  Montana Field Guide.  .  Retrieved on , from