Like most other
vittarioid ferns, members of the genus have simple, straplike leaves. Most species lack a
costa (midrib), although a few have a partial one, and the leaves are generally more than 1 centimetre (0.4 in) wide. The leaves have netlike venation, with three or more rows of areolae ("gaps" in the net of veins) on either side of the midline. Linear
sori are borne along the veins throughout the underside of the leaf.
Paraphyses (miniature hairs) are present on the sori (separating the genus from Polytaenium); the cells at the tips of the paraphyses may be spherical or slender, and
spores are trilete. (By comparison, Scoliosorus and Antrophyopsis always have spherical cells at the tips of their paraphyses, and monolete spores.)[3]
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",[4] 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.[5]
Species include:[6][7]
^"Antrophyum". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government, Canberra. Retrieved 2008-10-17.