Platycerium ellisii

Platycerium ellisii is an accepted naturally occurring species in Polypodiaceae and is endemic to Madagascar.

Reverend William Ellis collected the type material in Madagascar in 1870, and John Gilbert Baker formally described the species in 1876 in Ellis’s honor.

The species is confined to humid eastern Madagascar, where botanical records place it from sea level to about 400 m elevation.

P. ellisii grows as an epiphyte in humid lowland forest; one voucher was collected beside a river at 180 m, 10–15 m above the ground on a tree.

Shield fronds are sessile, approximately 20–30 by 15–20 cm, rounded and entire above, and remain pressed against the support as they age.

Fertile fronds are erect, wedge-shaped to obovate, 30–60 cm long, and entire or divided once, with one or rarely two broad apical spore patches.

The combination of rounded crownless shields and broad fertile fronds divided no more than once distinguishes mature P. ellisii from the more repeatedly divided P. alcicorne and the waffle-shielded P. madagascariense.

P. ellisii grows in clusters and may produce basal offsets that allow clonal division.

The species can be propagated sexually from spores and clonally by separating established basal offsets with roots and a viable growing point.

Molecular studies place P. ellisii within the Afro-Madagascan branch of Platycerium, but current plastid and nuclear analyses do not all recover the same closest relative.

Platycerium ellisii has glossy foliage. Young fertile fronds can be triangular, and some become forked as the plant matures.