New York Natural Heritage Program
Appalachian Bristle Fern
Trichomanes intricatum Farrar
Ferns
Trichomanes intricatum mass on rock face Kimberly J. Smith
Family: Filmy-fern Family (Hymenophyllaceae)

State Protection: Endangered
listed species are those with: 1) 5 or fewer extant sites, or 2) fewer than 1,000 individuals, or 3) restricted to fewer than 4 U.S.G.S. 7 minute topographical maps, or 4) species listed as endangered by U.S. Department of Interior.

Federal Protection: Not Listed

State Rarity Rank: S1
A State Rarity Rank of S1 means: This plant is endangered/critically imperiled in New York because of extreme rarity (typically 5 or fewer populations or very few remaining individuals) or is extremely vulnerable to extirpation from New York due to biological factors.

Global Rarity Rank: G4G5
A Global Rarity Rank of G4G5 means: Apparently or Demonstrably Secure globally - Uncommon to common in the world, but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign a single conservation status.


Did you know?
This fern exists only in the gametophyte form but at one time, before glaciation, there may have been sporophyte plants that produced spores that allowed the species to expand its range. The author of the species, Donald Farrar, postulates that the loss of sporophytes may have been due to climate change after the Pleistocene Epoch and there still exists the possibility that they remain undiscovered somewhere in the Appalachian Mountains (Farrar 1992).

State Ranking Justification [-]
There are three existing populations but only one of them has been seen since 1983 and it was very small. There are four historical populations from the Catskills and Hudson Valley area that have not been surveyed.

Short-term Trends [-]

Long-term Trends [-]