海南滨禾蕨 hai nan bin he jue

Type: China. Hainan: Five Finger Mountain [Wuzhi Shan], 1830 m, 30 Jan 1923, E. Smith 1548 (holotype, K!; isotype, SING!).

Oreogrammitis hainanensis resembles O. reinwardtii in having the acroscopic vein branch very short and not extending beyond the sorus, but it differs in having the veins invisible and stipe hairs shorter. It differs from O. sinohirtella in having a longer stipe and lamina and mostly shorter stipe hairs.

Stipe 11-16 mm, with dense simple solitary pale to dark reddish brown hairs 0.1-0.5 mm; phyllopodia absent. Lamina narrowly elliptic, 7.2-11 × 0.7-0.8 cm, gradually attenuate or cuneate to stipe, margin entire, apex acute to acuminate; midrib brown, slightly prominent abaxially, plane to grooved adaxially; lateral veins hidden, 1-forked, acroscopic branch shorter than basiscopic branch, not extending beyond sorus, endings with hydathodes; hairs occasional to scattered on all parts of lamina, simple, solitary, medium reddish brown, 0.1-2.6 mm. Sori orbicular or elliptic, superficial, close to midrib. Sporangia setose.

● Rupestral in mountain forests; 700-1400 m. Hainan.