''Didymoglossum petersii'', the dwarf bristle fern, is a species in the family

Hymenophyllaceae The Hymenophyllaceae, the filmy ferns and bristle ferns, are a family of two to nine genera (depending on classification system) and about 650 known species of ferns, with a subcosmopolitan distribution, but generally restricted to very damp pla ...

, (filmy ferns). It is one of three filmy ferns native to a significant area of the United States. It is found only in the nine most southeastern states, south of the Kentucky/Virginia - Tennessee/North Carolina dividing line, as well as in

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

and

Guatemala Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

. The genus '' Didymoglossum'' is accepted in the

Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discove ...

classification of 2016 (PPG I), but not by some other sources. , ''

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

'' merged the genus into a broadly defined ''

Trichomanes ''Trichomanes'' is a genus of ferns in the family Hymenophyllaceae, termed bristle ferns. The circumscription of the genus is disputed. All ferns in the genus are filmy ferns, with leaf tissue typically 2 cells thick. This thinness generally nec ...

'', treating this species as ''Trichomanes petersii''.

References

Hymenophyllales {{Polypodiidae-stub