Climbing Fern

kerstenii: named after Otto Kersten ( 1839-1900), a German plant collector

Climbing fern. Rhizome creeping, scales linear, blackish-brown, c. 1.5 mm long. Fronds spaced apart, growing to 6-12-20 m high. Stipe and rhachis of an elongated frond function as the climbing stem, from which short secondary rhachises with an opposing pair of pinnae arrise, apical bud densely covered with short brown hairs. Sterile pinnae bipinnate to 3-pinnate or 4-pinnatifid on the basal pinnae, margins toothed to lobed; pinnules lanceolate-oblong, up to 11 cm long,finely hairy along secondary rhachises and the pinnule midribs, veins with scattered hairs on both surfaces. Fertile pinnae bipinnate to 4-pinnate, veins hairy on both surfaces; fertile pinnules up to 9 cm long, with numerous protruding fertile lobes, up to 12 mm long; sporangia 4-14 pairs, arranged in 2 rows along the margins (pinnule apex without fertile lobes).

Mozambique, South africa, Swaziland, Zambia, Zimbabwe, from central Africa northwards to Kenya, also in Comores and Madagascar.