Greek platys, flat, + keras, hom, in reference to the flat, antlerlike shape of the fronds.

Plants medium-sized, epiphytic. Rhizomes short, usually completely obscured by fronds. Fronds of 2 kinds, both densely covered with soft, stellate hairs when young: sterile fronds broad, round to kidney-shaped, flattened against the substrate, persistent, often dry and brown, erect, overlapping, forming a basal "nest" or "basket";fertile "stag hom" fronds erect to pendent, entire or branched into narrow, elongated segments, coriaceous. Veins anastomosing, forming areoles with free, included veinlets. Sori in large patches apically or medially on abaxial surface of fertile blades, exindusiate.

A genus of fifteen species from Africa, Madagascar, Asia, Australia, Indonesia, the Philippines, and South America; popular in horticulture. Represented in Hawai 'i by two naturalized species, both potentially serious invaders of native forests.

KEY TO THE SPECIES OF PLATYCERIUM NATURALIZED IN HAWAI'I

1. Fertile fronds with irregular patches of sporangia covering ultimate tips of
straplike lobes of fertile fronds ........................... 1. P. bifurcatum

I. Fertile fronds with a single patch of sporangia projecting into sinuses of first
forks of fertile fronds ................................... 2. P. superbum