海南双盖蕨 hai nan shuang gai jue

Diplazium platylepis Ching.

Rhizome creeping or oblique, apex densely scaly; scales black, glossy, ovate-lanceolate, thickly membranous, subserrate at margin; fronds caespitose. Fertile frond ca. 1.6 m; stipe black at base, upward dark stramineous, ca. 90 cm, ca. 7 mm in diam., base sparsely scaly, upward glabrous; rachis brown-stramineous, glabrous; lamina ovate or elliptic, ca. 70 × 30 cm; lateral pinnae 2-8 pairs, oblique, shortly stalked or upper pinnae sessile, elliptic-lanceolate or ovate-lanceolate, ca. 32 × 7 cm, gradually narrowed at apex, base rounded-cuneate, slightly asymmetrical, entire at margin, slightly incurved; apical pinna similar to lateral pinnae; costae raised, rounded on abaxial side, shallowly grooved on adaxial side; veinlets slightly visible, oblique or slightly so, 3(or 4) per veinlet group, thin, subspreading, reaching margin. Lamina subleathery, green when dry. Sori and indusia long linear, mostly double, occasionally double on catadromous veinlets, but short.

Evergreen broad-leaved forests, beside streamlets; ca. 1200 m. Hainan [Vietnam].