Antrophyum


Antrophyum is a genus of ferns in the family Pteridaceae. They are commonly known as lineleaf ferns.

Description

Like most other vittarioid ferns, members of the genus have simple, straplike leaves. Most species lack a costa, although a few have a partial one, and the leaves are generally more than wide. The leaves have netlike venation, with three or more rows of areolae on either side of the midline. Linear sori are borne along the veins throughout the underside of the leaf. Paraphyses are present on the sori ; the cells at the tips of the paraphyses may be spherical or slender, and spores are trilete.

Taxonomy

The genus was first described by Georg Friedrich Kaulfuss in 1824. He included in it several species placed in Hemionitis by Carl Ludwig Willdenow, distinguishing them on the basis of their reticulate, indusiate sori sunken into the leaf tissue. The name means "growing from a cavity", a reference to the growth of the sori from a groove in the leaf. In 1875, John Smith designated Antrophyum plantagineum as the lectotype for the genus.
Species include:
The subgenus Antrophyopsis, containing the species A. bivittatum C. Chr., A. boryanum Willd., and A. mannianum Hook., was elevated to a genus in 2016.

Distribution

Most species occur in tropical Asia and the Pacific, but A. immersum and A. malgassicum are known from Africa and the Indian Ocean.