Description from Flora of China
Davallia trapeziformis Roxburgh, Calcutta J. Nat. Hist. 4: 516. 1844; Microlepia rhomboidea (Wallich ex Kunze) Prantl var. trapeziformis (Roxburgh) Prantl; M. trichoclada Ching; M. yaoshanica Ching; M. yunnanensis Ching.
Plants terrestrial. Rhizome creeping, deep brown, ca. 6 cm in diam., sparsely long gray bristly. Fronds distant; stipe straw-colored to grayish straw-colored, 30-60 cm, 3-4 mm in diam., almost glabrous, base sparsely hairy and with coarse marks. Lamina dark green when dried, 3-pinnate, broadly lanceolate in outline, 50-60 × 25-40 cm at middle, herbaceous, abaxially with dense, long, gray, shiny, appressed, acicular hairs, as in all rachillae abaxially, adaxially sparsely long acicular hairy or almost glabrous, apex subcaudate and acuminate; pinnae 15 pairs or more, alternate, 6-9 cm apart, spreading obliquely upward, with stalk ca. 1 cm, lower 6 or 7 pairs bipinnate, others 1-pinnate, basalmost pair slightly shorter, second pair broadly lanceolate to narrowly oblong-lanceolate, 17-24 × 5-7 cm, base broad, asymmetrical, basiscopically cuneate, acroscopically auriculate and parallel with pinna rachis, basiscopic lobe usually covering rachis, apex long acuminate; pinnules ca. 20 pairs, alternate, anadromous, compact, spreading, shortly stalked, 1-pinnate or pinnatisect to narrowly winged rachillae, oblong, 2-4 × 1-1.5 cm, acroscopic lobes longest, base asymmetrical, basiscopically cuneate, acroscopically truncate and parallel with pinna rachis, apex rounded or acute; distal pinnules 5-10 pairs, adjacent, spreading obliquely upward, oblong, 5-7 × 3-4 mm, base cuneate, somewhat decurrent along rachillae, entire or with 1 or 2 shallow notches, acroscopic side wider, usually with 2 or 3 acroscopic lobes, with basal pinnules largest, parallel to rachilla, apex rounded. Veins slender, obvious on both surfaces, pinnately furcate, simple, or furcate in large lobules, not reaching margin. Sori orbicular, small, on top of ultimate lobes, distant from margin; indusium greenish, hemitelioid, small, very broad, with long hairs.
Fraser-Jenkins (Taxon. Revis. Indian Subcontinental Pteridophytes, 84. 2008) believes that Microlepia trapeziformis is a synonym of M. pilosiuscula (Smith) C. V. Morton. Reviewer Ralf Knapp suggests that the records from Taiwan are based on material of the following species, M. rhomboidea.
Forests; 500-1900 m. Guangdong, Guangxi, Hainan, Taiwan, Xizang, Yunnan [India, Indonesia, Malaysia, Myanmar, Philippines, Thailand, Vietnam].