Polypodium speluncae Linnaeus, Sp. Pl. 2: 1093. 1753; Aspidium speluncae (Linnaeus) Willdenow; Davallia flaccida R. Brown; D. polypodioides (Swartz) D. Don; D. polypodioides var. pilosa Hooker; D. polypodioides var. pubescens Hooker; D. speluncae (Linnaeus) Baker; D. villosa D. Don; Dennstaedtia villosa (D. Don) Copeland; Dicksonia polypodioides Swartz; Microlepia flaccida (R. Brown) J. Smith; M. ganlanbaensis Ching; M. hispidula Alderwerelt; M. intermedia Ching; M. mollifolia Tagawa; M. pilosissima Ching; M. pingpienensis Ching; M. polypodioides (Swartz) C. Presl; M. puberula Lacaita (1916), not Alderwerelt (1913); M. puberula f. pilosior Lacaita; M. pyramidata Lacaita; M. speluncae var. hirta Beddome; M. speluncae var. pubescens (Hooker) Sledge; M. speluncae var. pyramidata (Lacaita) Tardieu & C. Christensen; M. subrhomboidea Ching; M. subspeluncae Ching; M. villosa (D. Don) Ching (1959), not C. Presl (1851).

Plants terrestrial, 1.2-1.5(-2) m tall. Rhizome creeping, more than 7 mm in diam., glabrescent. Fronds scattered; stipe straw-colored, ca. 50[-70] cm, stiff, usually with dense, short, gray-brown, segmented hairs; rachis and rachillae also straw-colored, with scattered soft hairs. Lamina yellow-green when dried, 3- or 4-pinnate, ovate-oblong in outline, 60-100 × 30-40[-50] cm, thinly papery, both surfaces with often dense, adpressed, slender hairs, base wider, gradually shorter distally, apex acuminate; pinnae 10-15[-20+] pairs, alternate, 10-15 cm apart, spreading obliquely upward, with stalk 1-1.5 cm, bipinnate, broadly lanceolate in outline, lowermost pinnae slightly smaller, largest pinnae 28-30 cm, 10-15 cm wide at base, apex long acuminate; pinnules 15-20 pairs, upswept, parallel with rachis, broadly lanceolate, 2.5-4 × 0.8-1 cm, pinnatisect almost to rachillae, base unequal in width, decurrent, cuneate basiscopically, subtruncate acroscopically, apex acuminate; distal lobes 6-8 pairs, suprabasal ones longer, parallel with rachillae, others oblong, 7-8 × ca. 4 mm, truncate acroscopically, straight-cuneate basiscopically, margin obtusely pinnatifid, apex rounded; lobules entire or apex with 2 or 3 dwarf obtuse teeth. Veins slightly prominent abaxially, pinnately branching. Sori near notch at margin of lobules; indusium brownish, shallowly saucer- or fan-shaped, small, firm, densely hairy.

"Microlepia pilosula" (C. Presl, Tent. Pterid. 125. 1836, nom. nud.), based on "Davallia pilosula" (Wallich, Numer. List, no. 263. 1839, nom. nud.), probably belongs here. It has also been placed within M. trapeziformis.

Roadsides, shrublands; below 100-1100 m. Guangdong, Guangxi, Guizhou, Hainan, Taiwan, Xizang, Yunnan [Bhutan, Cambodia, India, Indonesia, Japan (Ryukyu Islands), Laos, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam; Africa, Australia (Queensland), Pacific islands (Polynesia), South America (Brazil), West Indies].