胄叶线蕨 zhou ye xian jue

Polypodium hemitomum Hance, J. Bot. 21: 269. 1883; Colysis hemitoma (Hance) Ching; C. hemitoma f. integra Ching ex S. H. Fu; P. cavaleriei Rosenstock; P. phyllomanes Christ var. hemitomum (Hance) Christ.

Rhizome slender, long creeping; scales dark brown, ovate-lanceolate, 1-4.6 × 0.2-1 mm, margin denticulate, apex long acuminate. Fronds monomorphic or slightly dimorphic, distant; stipe pale brown, 5-30 cm; lamina simple to irregularly pinnatifid lobed, ovate, broadly deltoid-lanceolate, or sagittate, 10-25 × 3-15 cm, herbaceous, glabrous, base truncate, apex long acuminate; lobes when present 1-3 pairs, linear-lanceolate, 3-10 × 0.6-1.8 cm, margin undulate; veinlets forming 2 rows of areoles between 2 adjacent lateral veins, free included veinlets simple or forked. Sori linear, 1 regular row between lateral veins, up to margin of lamina, sometimes incompletely covered by peltate paraphyses when young.

Valley forests. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Sichuan, Zhejiang [Japan, Indonesia, Malaysia, Vietnam].

Nooteboom (Blumea 42: 294. 1997) regarded Leptochilus ×hemitomus as a hybrid between L. macrophyllus (Blume) Nooteboom and L. ellipticus on the basis of the irregular frond shape and abortive sporangia.