Identity
Unique IDELEMENT_GLOBAL.2.154804
Element CodePPHYM020V0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumFilicinophyta
ClassFilicopsida
OrderFilicales
FamilyHymenophyllaceae
GenusCrepidomanes
SynonymsTrichomanes intricatumFarrar
Other Common NamesAppalachian Trichomanes (EN) Grotto-felt (EN) weft fern (EN)
Concept ReferenceKartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
Taxonomic CommentsEbihara and Weakley (in Weakley et al. 2011) newly combine Crepidomanes intricatum due to its chloroplast molecular sequence data similarity with the Old World genus, Crepidomanes. This concept is synonymous with Trichomanes intricatum as recognized by FNA (1993, vol. 2) and Kartesz (1999). The generic placement of this taxon is in accordance with the Pteridophyte Phylogeny Group I (2016).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-05-07
Change Date2025-05-07
Edition Date2025-05-07
Edition AuthorsMorse, Larry E. (1994), rev. N. Ventrella (2025)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences21 - 300
Rank ReasonsCrepidomanes intricatum is a fern occurring on non-calcareous rock in moist, well-sheltered crevices and grottoes of eastern North America, primarily in the Appalachian region, though ranging from Quebec, Canada and New Hampshire south to Georgia and Alabama, and north to Illinois in the United States. This species does not produce sporophytes, and populations consist of filamentous, asexually reproducing gametophytes forming feltlike populations resembling algae. Though considered rare to uncommon throughout its range, this species is widespread, easily overlooked, difficult to distinguish from gametophyte forms of similar species, and is likely underrepresented in herbaria. Threats include invasive species, logging, recreation, and likely other threats in some places .
Range Extent CommentsCrepidomanes intricatum occurs in eastern North America, primarily in the Appalachian region, though ranging from Quebec, Canada and New Hampshire south to Georgia and Alabama, and north to Illinois in the United States (FNA 1993, Centre de Donnees sur le Patrimoine Naturel du Québec 2025). Range extent was estimated using herbarium specimens and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are at least 27 occurrences rangewide (GBIF 2025, NatureServe 2025, RARECAT 2025, SEINet 2025). However, due to its gametophytic habit, Crepidomanes intricatum is extremely inconspicuous, easily overlooked, difficult to identify, and likely underrepresented in herbarium collections (FNA 1993, Weakley and the Southeastern Flora Team 2025).
Threat Impact CommentsAlthough threats are not widely documented, Crepidomanes intricatum occurs in humid places in sheltered crevices and grottoes, and it may be at least somewhat protected by its habitat. Threats to this species are not well documented but include invasive species, logging, recreation, and likely other threats in some places (NatureServe 2024).