Oleandra sibbaldii
Oleandra sibbaldii Grev.
Oleandra sibbaldii is a fern species in the Oleandraceae family, native to several Pacific and Southeast Asian islands. It has a long-creeping or pendulous rhizome with peltate scales and monomorphic fronds. The fronds have a membranous to coriaceous texture, with sori located inframedially and a distinct sterile zone between the costa and soral zone. Spores exhibit a mesh-like network with fine papillae.
Description
Oleandra sibbaldii has a rhizome that is long-creeping or pendulous, sparsely branched, and covered with peltate scales that are reddish brown and often glandular. The fronds are monomorphic, with stipes that can be up to 4.5 cm long and often dark on the abaxial side. The lamina is widest in the middle, with an acuminate or caudate apex. Sori are inframedial, with a sterile zone between the costa and soral zone, and the indusium is firm and hairy. Sporangial stalks have glands below the sporangium, and spores have an irregular mesh-like network with fine papillae. This species is common in New Guinea but less so in peripheral regions of its distribution.
Distribution
Borneo · Fiji · Maluku · Marquesas · New Guinea · Philippines · Samoa · Society Is. · Solomon Is. · Sulawesi · Vanuatu
Synonyms
Oleandra crassipesOleandra gracilisOleandra ornataOleandra tricholepisOleandra whitmeeiOleandra cumingii var. sibbaldiiOleandra whitmeei var. minor