Antrophyum sect. Loxogramme Blume, Fl. Javae Filic. 73. 1829.

Rhizome very shortly to long creeping, occasionally branching; roots forming a spongy mass; scales clathrate, uniformly orange-brown to blackish, entire, elongate, basifixed. Articulation between phyllopodium and frond none, or evident but not functional, or functional. Entire plant, except for roots, lacking sclerenchyma. Lamina simple, monomorphic to dimorphic, linear, narrowly elliptic, oblanceolate, or spatulate to orbicular, entire, thinly to thickly papery, margin not cartilaginous, drying revolute or involute. Lamina surface glabrous except for minute 2-celled clavate glandular hairs. Veins regularly anastomosing with many, few, or without free included veinlets; hydathodes absent. Sori exindusiate, elongate, oblique or subparallel to costa, discrete, paraphyses multicellular, hairlike. Sporangial stalk 1- or 2-celled at base; annulus with 12-16 hardened cells. Spores greenish (at time of dispersal), globose-trilete, or ellipsoid-monolete, surface finely verrucose. n = 35, 36.

Holttum (Revis. Fl. Malaya 2: 167. 1954) suggested that the lack of articulation possibly causes the fleshy nature of the fronds, which curl up in dry weather.

Molecular data consistently indicate that Loxogramme is sister to the rest of the Polypodiaceae.

The following taxa are excluded from the present treatment, pending further research: Loxogramme elevata Ching (Bull. Fan Mem. Inst. Biol., n.s., 1: 298. 1949), described from Yunnan, L. linearis Copeland (Philipp. J. Sci., C, 11: 45. 1916), described from Taiwan, and Gymnogramma lanceolata (Linnaeus) T. Moore var. minor Baker ex Makino (Bot. Mag. (Tokyo) 10: 178. 1896).

About 33 species: pantropical, mainly in tropical Asia, one in Central America, one on Pacific islands, four in Africa; 12 species (one endemic) in China.

(Authors: Zhang Xianchun (张宪春); Michael G. Gilbert)