Stenochlaena J.Sm.

Moderate to large, high-climbing ferns with scandent rhizomes, often in swamps or beside rivers. Rhizome naked, green, apically bearing many rotund or elongate, peltate scales, radially symmetric, vascular system a complex dictyostele of several large central bundles surrounded by 2 irregular rings of many smaller bundles. Fronds widely spaced, stipes glabrous, ± decurrent with the rhizome, with corresponding vasculature, the lamina pinnate with alternate pinnae and a terminal pinna similar to the lateral pinnae, dimorphic, the fertile lamina much contracted (in one species bipinnate); the sterile lateral pinnae usually articulate, with a basal acroscopic gland, costate with fine, close, free veins arising from a series of narrow, elongate, costal areoles, coriaceous, glabrous, margin cartilaginous and sharply toothed; fertile pinnae narrow, linear, entire. Sporangia borne in an elongate coenosorus occupying the area from the costal areoles almost to the margin of the fertile pinnae, supplied by a secondary vascular system, exindusiate, paraphyses lacking, annulus longitudinal, interrupted, of 12-20 thickened cells. Spores monolete, translucent, tuberculate or with continuous or broken ribs.