Gymnosphaera Blume.

Plants treelike; trunk erect, rarely branching, or creeping, shrublike, apices covered with scales. Fronds large; stipe stramineous, dark brown, or black, smooth, spiny, or warty; scales brown or dark brown, margin differentiated; lamina 1-3-pinnate; veins simple or forked. Sori orbicular, dorsal on veinlets; indusia various in form or absent, paraphyses present. x = 69.

Most species have an indusium, but this structure may be lost as the frond matures; in some species, the indusium is absent. The Chinese species in Alsophila subg. Alsophila all have an indusium; the species of A. subg. Gymnosphaera (Blume) Q. Xia are all without an indusium.

About 230 species: pantropical, extending into the S temperate zone as far as the subantarctic Auckland Islands; plants of cold or wet montane forests, on slopes or in ravines, and low canopy, middle understory, or ground cover; 20 species in Asia; 12 species (one endemic) in China.