Mertensia Willdenow (1804), not Roth (1797).

Rhizomes creeping, covered with scales. Fronds distant, erect; lamina often repeatedly pseudodichotomously divided, without lateral pinnules at dichotomies, upper axes pinnulelike with rows of lobes along each side; lamina gray-green or glaucous abaxially; veins once forked. Sori orbicular, exindusiate, in 1 line on each side of costule; sporangia 4 or 5(or 6), sessile; spores 2-sided or reniform, monolete.

Some authorities (e.g., Botany Vietnam Group, http://www.botanyvn.com/cnt.asp?param=edir&v=Gleichenia%20truncata&list=species&lg=en; accessed 4 Jul 2012) follow Holttum (Fl. Males., Ser. 2, 1: 20, f. 7a-b & 9. 1959) who included Sticherus (and Diplopterygium) within Gleichenia Smith and S. laevigatus within S. truncatus.

About 100 species: tropical areas, mainly distributed in South America; one species in China.

(Authors: Ding Bingyang (丁炳扬), Jin Xiaofeng (金孝锋); Kunio Iwatsuki)