9. Haplopteris hainanensis (C. Christensen ex Ching) E. H. Crane, Syst. Bot. 22: 514. 1998.
海南书带蕨 hai nan shu dai jue
Vittaria hainanensis C. Christensen ex Ching, Sinensia 1: 182. 1931.
Rhizome shortly creeping, ca. 2 mm thick; scales dark brown, bright iridescent, linear-lanceolate, 5-10 mm, ca. 0.5 mm wide at base, apex bristlelike, marginal row of areole thin-walled, middle areole wall thick, dark colored. Fronds clustered; stipe absent; lamina very leathery, linear or lanceolate, 10-30 × 0.2-0.4(-1.1) cm, usually widest near middle, narrowed gradually to both ends, flattened to very base, margin strongly revolute; costa visible abaxially, sometimes adaxially, not raised; veins usually not evident. Soral line submarginal, immersed in deep groove, thus raised above; paraphyses long, with head obconic, ± as long as wide. Spores monolete, oval in outline, surface obscurely papillate.
On palm trees; 100-1000 m. Hainan, S Yunnan [N Vietnam].
Whether Haplopteris hainanensis is conspecific with H. ensiformis (Swartz) E. H. Crane or not is unclear.