Oleandra musifolia

Description. Rhizome creeping, 5 - 8 mm thick, white waxy in the older parts, often supported above the substrate by unbranched stilt-like roots, dorsiventrally flattened, (strongly compressed, 4 - 6 mm wide when dry), with up to 10 cm long, curved internodes (only occasionally straight and then often much longer) terminating in a cluster of a few short phyllopodia, usually less than 5 (- 15) mm long, often hidden by the scales, rhizome often innovating just below this cluster, lateral branches usually basal on the internodes, in opposite pairs; all parts in cross-section without or with few sclerified strands, roots scattered, with long unbranched aerial parts. Scales persistently covering the rhizome, peltate, 5 - 10 x 1 - 1.5 mm, appressed, with dark center and lighter brown acumen and margin, margin ciliate especially when young and with sessile glands. Fronds monomorphic, stipe 0.5 - 4 cm long, without dark colouration, with short, glandular hairs; lamina to 60 x 4.2 cm, linear, base cuneate to truncate or more or less rounded, apex acute to long-acuminate, texture thin-chartaceous, both surfaces with catenate, often glandular hairs 0.2 - 0.5 mm long; costa without dark colouration, on lower surface with inconspicuous, 1 - 3 mm long brown scales. Sori mostly in a single regular row close to the costa, sometimes more scattered over a 2 - 5 mm wide zone close to the costa or at a distance of up to 3 mm, indusium distinct, 1.5 - 2 mm wide, glabrous or glandular, sometimes setose. Sporangial stalk with glands below the sporangium. Spores with coarse confluent ridges, areolae with short pointed excrescences, perispore hollow, with internal baculae, outer layer not or hardly perforated.