珠芽狗脊 zhu ya gou ji

Woodwardia angustiloba Hance; W. exaltata Nakai; W. orientalis Swartz var. formosana Rosenstock; W. orientalis var. prolifera (Hooker & Arnott) Ching; W. prolifera var. formosana (Rosenstock) Ching.

Rhizome decumbent, dark brown, stout, densely scaly; scales red-brown, lanceolate, 2-4 cm, membranous, entire or with a few teeth, fibriform. Stipes close, 30-110 cm, 3-15 mm in diam., base densely scaly; upper part of stipe and rachis sparsely covered with brown, broadly lanceolate scales, surface rough with scale scars; lamina deeply bipinnatifid, brown or slightly green when dry, oblong-ovate or elliptic, 35-120 × 30-40 cm, leathery, glabrous, apex acuminate; pinnae 5-9(-13) pairs, shortly stalked, lanceolate; lower and middle pinnae 10-30 × 4-9 cm, deeply pinnatifid to 1-2 mm from costa, base asymmetrical with 1-3 basiscopic lobes lacking, apex long acuminate or caudate; lobes 10-14(-24) pairs, close or separate, oblique, oblong-lanceolate, 3-7(-9) × 0.5-0.9 cm, slightly narrowed to base, margin cuspidately serrulate, occasionally lobed, apex long acuminate or caudate; veins obvious, anastomosing with 1 row of areoles along costae and 2 or 3 rows of discrete, polygonal areoles, free distally, simple or forked. Leaf-bearing bulbils small and usually abundant on adaxial surfaces of pinna lobes. Sori occupying costular areoles, crescent-shaped or elliptic, sunken in rimmed depressions; indusia dark brown, thickly papery. 2n = 68.

Mountain slopes, open and wet places in sparse forests, near streams; 100-1100 m. Anhui, Fujian, Guangdong, Guangxi, Hunan, Jiangxi, Taiwan, Zhejiang [Japan].

Herbarium and field observations of Woodwardia prolifera show that there is ecological variation in the frequency of bulbils on the lamina; some mature fronds are not bulbiliferous.

The name "Woodwardia radicans (Linnaeus) Smith var. prolifera C. Christensen, Index Filic. 658. 1905" (Acta Phytotax. Sin. 12: 244. 1974; and FPRS 4(2): 201. 1999) appears to be a mistaken joining of the end of one line "= W. radicans var." with the beginning of another, the next species in the list, "prolifera."