Epiphytic ferns with fronds of moderate size. Rhizome creeping or bulbous, little- or much-branched, variously inflated, cavernous and inhabited by ants, +/- glaucous, glabrous (sect. Lecanopteris), or densely and persistently or sparsely and deciduously covered with peltate scales, (sect. Myrmecophila), bearing fronds in 2 rows. Fronds erect or ascending, stipes short to elongate, articulate to prominent, cavernous, conical phyllopodia, the lamina simple to deeply pinnatiafid, the costae or midribs prominent, the veins often obscure, the lateral veins zig-zag and not reaching the margin, a series of large areoles near the costa with branched included free veinlets and 1-2 series of smaller areoles, also with included free veinlets, towards the margin. Sori on concave marginal lobes (sect. Lecanopteris), or in a single row either side of the rib or costae (sect. Myrmecophila), borne on a vascular reticulum, generally immersed in the lamina, a single sorus between each pair of main veins centered on the outer margin of the first series of areoles, exindusiate, sporangia on a triseriate stalk, the annulus longitudinal, interrupted, of c.13 thickened cells; parphyses present or absent. Spores monolete, translucent, smooth.
Sect. Lecanopteris: Rhizome naked, much-branched. Frond deeply pinnatifid. Sori on concave marginal lobes, reflexed or not.
In Papuasia represented by Lecanopteris curtisii.
Sect. Myrmecophila: Rhizome persistently or deciduously clothed in orbicular peltate scales, little-branched. Fronds simple or pinnatifid. Sori in a single row between the costae or between the margin and the midrib.
In Papuasia represented by Lecanopteris sinuosa and Lecanopteris mirabilis.
Key to the species of Lecanopteris in Papuasia:
Species in Papuasia
|1a.||Fronds simple, short-stalked, with entire or undulate margins: rhizome tubular, c. 1 cm diameter, sparingly branched, completely covered with overlapping pale scales with dark centres; sori +/- medial and immersed in the lamina||L. sinuosa|
|Fronds deeply pinnatifid, long-stalked; rhizome bulbous or crust-like, 3 cm or more across, +/- glaucous, naked or with scattered, sparse, dark-centered scales; sori medial, either side of the costae, or immersed in small marginal lobes.||2|
|2a.||Sori deeply immersed in a medial row either side of the costa; rhizome broad and crust-like, arching over the trunk or branch of the host-tree, not branching, bearing scattered, dark-centered sales; fronds not glaucous||L. mirabilis|
|Sori in pockets at the apices of small marginal lobes; rhizome bulbous, +/- tubular, branching, naked; fronds +/- glaucous, at least beneath||L. curtisii|