乌蕨 wu jue

Trichomanes chinense Linnaeus, Sp. Pl. 2: 1099. 1753 ["chinensis"]; Adiantum chusanum Linnaeus; Davallia chinensis (Linnaeus) Smith (1793), not D. sinensis (Christ) Ching (1931, nom. cons.); D. chusana (Linnaeus) Willdenow; Lindsaea chinensis (Linnaeus) A. Braun & C. D. Bouché; Microlepia chinensis (Linnaeus) Mettenius; Odontosoria chusana (Linnaeus) Masamune; O. gracilis (Tagawa) Ralf Knapp; Sphenomeris chinensis (Linnaeus) Maxon; S. chusana (Linnaeus) Copeland; Stenoloma chinensis (Linnaeus) Beddome; S. chusanum (Linnaeus) Ching; S. gracile Tagawa.

Rhizomes shortly creeping, densely scaly; scales dark brown, ca. 2 mm, narrow, 1 or 2 cells wide at base, acicular at apex, stiff. Stipe stramineous to dark stramineous, 20-30 cm, abaxially sulcate except at base; lamina ovate-oblong to lanceolate, 20-50 × 5-15 cm, firmly herbaceous to papery, 3- or 4-pinnate, widest at middle, base broadly cuneate, apex acuminate; pinnae 15-20 pairs, alternate, patent to slightly ascending, ovate-lanceolate, 3-pinnate at base, base cuneate and shortly stalked, margin denticulate to erose, apex acuminate; ultimate pinnules or segments cuneate, to 4 mm wide, apex broadly rounded to truncate or shallowly lobed; veins visible on abaxial surface, forked in ultimate lobes. Sori terminal on 1 or uniting 2 or 3 vein ends; indusia basally and partially adnate laterally, denticulate to erose, rarely repand, distinctly shorter than or rarely coterminous with adaxial lamina. Spores ellipsoid, monolete. 2n = 96, 192.

Terrestrial, along roadsides, forest margins; 300-1700 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Bangladesh, Bhutan, India, Japan, Korea, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam; Madagascar, Pacific islands (including Polynesia)].

Knapp differentiated Odontosoria gracilis from O. chinensis by its rheophytic habit, creeping rhizome, narrowly triangular scales, and thinly herbaceous narrowly ovate lamina and indicated that the two taxa hybridize. One of us (Barcelona) reviewed the type of O. gracilis and considers it to be a synonym of the very variable O. chinensis.