Trichomanes intricatum is known as the weft fern. This is an unusual filmy fern that grows in rock shelters and crevices in the eastern United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, being known only from its gametophyte

Gametophyte

A gametophyte is the haploid, multicellular phase of plants and algae that undergo alternation of generations, with each of its cells containing only a single set of chromosomes....

 generation. It is a rare plant that is protected in several states.

Recent study has found a relationship between this species and an Asian filmy-fern species, Crepidomanes schmidtianum. Both share the same chloroplast

Chloroplast

Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...

 genome

Genome

In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

. The relationship is uncertain.