大久保对囊蕨 da jiu bao dui nang jue

Athyrium okuboanum Makino, Bot. Mag. (Tokyo) 13: 16. 1899; A. unifurcatum (Baker) C. Christensen var. okuboanum (Makino) H. Itô; A. viridifrons Makino f. okuboanum (Makino) Makino; Dryoathyrium okuboanum (Makino) Ching; D. viridifrons (Makino) Ching var. okuboanum (Makino) Ching ex S. H. Fu; Dryopteris okuboana (Makino) Koidzumi; Lunathyrium okuboanum (Makino) Sugimoto; L. unifurcatum Kurata var. okuboanum (Makino) Sa. Kurata.

Rhizomes creeping, ascending at apex. Fronds subcaespitose; fertile fronds up to 1.2 m; stipe upward stramineous, 30-50 cm, 3-5 mm in diam. at base, with sparse brown lanceolate scales, upper part glabrate; lamina 3-pinnatifid or 3-pinnate, broadly ovate or ovate-oblong, 30-80 × 25-40 cm, base rounded-cuneate and narrowed, apex acuminate; pinnae 10-14 pairs, alternate, shortly stalked or subsessile, oblong-lanceolate, 20-28 × 5-9 cm, narrowed toward base, acuminate at apex; pinnules 12-16 pairs, basal pinnules subopposite, other pinnules alternate, sessile, spreading, basal pinnules smaller, oblong, 1-1.2 cm × ca. 5 mm, subequilateral, obtuse-rounded; large pinnules oblong, 3-8 cm × 7-15 mm, base broadly cuneate, decurrent and adnate to costules with narrow costular wings, shallowly lobed to pinnatipartite, apex obtuse to acuminate; segments oblong, oblique, entire, obtuse-rounded. Veins pinnate in segment, lateral veins 2-4 pairs, simple. Lamina thickly papery when dried, grass-green, rachis, costae, and costules with sparse brownish broadly lanceolate small scales and scalelike vermiculate hairs. Sori orbicular, abaxial; indusia greenish brown, orbicular-reniform or somewhat horseshoe-shaped, membranous, entire or laciniate, persistent. Perispore with baculate or spinelike ornamentation. 2n = 120 (apomictic).

Valley forests, forest margins, wet areas, streamsides; near sea level to 2500 m. Anhui, Fujian, SE Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, S Shaanxi, Sichuan, Yunnan, Zhejiang [Japan, Vietnam].