单叉对囊蕨 dan cha dui nang jue

Nephrodium unifurcatum Baker, J. Bot. 26: 228. 1888; Aspidium pandiforme Christ; Athyrium unifurcatum (Baker) C. Christensen; Dryoathyrium jinfoshanense Ching & Z. Y. Liu; D. unifurcatum (Baker) Ching; Dryopteris pandiformis (Christ) C. Christensen; D. tosensis Kodoma; D. unifurcata (Baker) C. Christensen; Lunathyrium unifurcatum (Baker) Kurata; Parathyrium unifurcatum (Baker) Holttum.

Rhizomes long creeping. Fronds distant; fertile fronds 45-95 cm; stipe upward stramineous, 20-40 cm, 2-3 mm in diam. at base, base with sparse blackish brown broadly lanceolate or linear scales, upper part glabrate; lamina 2-pinnatifid, ovate-oblong, 25-55 × 20-28 cm, base slightly narrowed, apex acuminate; pinnae 12-14 pairs, basal pinnae subopposite, other pinnae alternate, subsessile, ascending, lanceolate, middle pinnae 13-16 × 3-4 cm, base narrowed and rounded-truncate, pinnatipartite, apex acuminate; segments 12-15 pairs, oblong, basal segments shortened, upper segments 1.5-2.5 cm × 6-8 mm, entire or crenate, obtuse-rounded or truncate. Veins pinnate in segment, lateral veins forked, occasionally 3-forked. Lamina herbaceous when dried, pale green, rachis, costae, and costules with sparse black or dark brown lanceolate small scales and brown, scalelike vermiculate hairs. Sori small, orbicular, abaxial, medial; indusia red-brown, small, orbicular-reniform, membranous, subentire or laciniate, persistent. Perispore with baculate or spinelike ornamentation. 2n = 80*, 160; n = 2n = 120 (apomictic).

Mountain forests, damp areas at streamsides, wet broad-leaved forests; 200-2800 m. Chongqing, Guizhou, Hubei, Hunan, S Shaanxi, Sichuan, Taiwan (Hualian, Nantou), Yunnan, Zhejiang [Japan].