Acrostichum longifolium N. L. Burman, Fl. Indica, 228. 1768; Candollea longifolia (N. L. Burman) Mirbel; Cyclophorus acrostichoides (G. Forster) C. Presl; C. induratus Christ; C. longifolius (N. L. Burman) Desvaux; C. macropodus (Baker) C. Christensen; C. scolopendrium Desvaux; Niphobolus acrostichoides (G. Forster) Beddome (1868), not Kaulfuss (1824); N. longifolius (N. L. Burman) Sprengel; N. scolopendrium (Desvaux) T. Moore; Polypodium acrostichoides G. Forster; P. macropoda Baker; Pyrrosia acrostichoides (G. Forster) Ching; P. coccideisquamata Gilli; P. macropoda (Baker) Ching.

Plants 20-50 cm tall. Rhizome long creeping, 1.8-2.7 mm in diam., in cross section with many scattered sclerenchyma strands; phyllopodia 2-6 cm apart, lateral buds alternating with phyllopodia. Scales peltate, 1-3.4 × 0.6-1.5 mm, shiny brown or blackish with a distinct, light colored, entire margin. Fronds monomorphic, distinctly to indistinctly stipitate; stipe 1.5-5 cm; lamina strap-shaped, 16-60 × 1-3 cm, often ± narrowed in fertile part, base ± gradually narrowed, apex acute to rounded. Hydathodes absent. Indument sometimes fugacious, monomorphic, sparse or thin; hairs 0.3-0.4 mm in diam., with appressed, boat-shaped rays. Sori sunken, with central bundle of stellate paraphyses. Sporangia with stalks up to 2 × as long as capsule.

Small plants of Pyrrosia longifolia can be superficially similar to P. lanceolata or P. nuda but are best distinguished by the completely entire rhizome scales (ciliate in P. lanceolata and P. nuda).

On tree trunks or shaded wet rocks in forests; 300-1400 m. Hainan, Yunnan [Cambodia, Indonesia, Laos, Malaysia, Myanmar, New Guinea, Philippines, Singapore, Thailand, Vietnam; SW Asia, Australia, Pacific islands].