Maidenhair Spleenwort - Asplenium trichomanes
State Rank Reason (see State Rank above)
Known from one 1895 collection with imprecise location data near "Columbia Falls" in Flathead County.
Maidenhair Spleenwort is a perennial with short rhizomes and glabrous, evergreen fronds clustered from the base of the plant. Each frond is 7-35 cm long, and is pinnately divided into numerous pinnae that are arranged alternately on the shiny, reddish-brown central axis (rachis) of the frond. The naked petioles and central axes tend to persist after the pinnae have fallen; each pinna is 5 mm wide and entire-margined below, but shallowly lobed toward the tip. Spores are borne in 1-4 clusters arranged along the veins on the undersides of the pinnae; the spores are partially enfolded by a thin, white tissue, the indusium.
Fronds mature in June-July.
This species can be distinguished from the more common A. viride by its shiny, reddish-brown leaf stems.
One MT collection from Flathead County over 100 years ago; circumboreal south to CA, AZ, NM GA, and Mexico (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Moist rock crevices and talus slopes in the montane zone.
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
- Literature Cited AboveLegend: View Online Publication
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Additional ReferencesLegend: View Online Publication
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- Lellinger, D.B. 1985. A Field Manual of the Ferns and Fern-Allies of the United States and Canada. Smithsonian Inst. Press. Washington, D.C. B85LEL01PAUS
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
- Moran, R. C. 1982. The Asplenium trichomanes complex in the United States and adjacent Canada. American Fern Journal 72(1): 5-11.