Plants mostly epiphytic and epilithic, a few terrestrial. Rhizomes shortly to long creeping, dictyostelic, bearing scales. Fronds monomorphic or dimorphic, mostly simple to pinnatifid or 1-pinnate (uncommonly more divided); stipes cleanly abscising near their bases or not (most grammitids), leaving short phyllopodia; veins often anastomosing or reticulate, sometimes with included veinlets, or veins free (most grammitids); indument various, of scales, hairs, or glands. Sori abaxial (rarely marginal), orbicular to oblong or elliptic, occasionally elongate, or sporangia acrostichoid, sometimes deeply embedded, sori exindusiate, sometimes covered by caducous scales (soral paraphyses) when young; sporangia with 1-3-rowed, usually long stalks, frequently with paraphyses on sporangia or on receptacle; spores hyaline to yellowish, reniform, and monolete (non-grammitids), or greenish and globose-tetrahedral, trilete (most grammitids); perine various, usually thin, not strongly winged or cristate. Mostly x = 35, 36, 37.

The Polypodiaceae s.s., as often recognized, are paraphyletic because they exclude the grammitids. Generic boundaries need clarification. Polypodiaceae contain large, wholly neotropical and wholly paleotropical clades.

Molecular data show that several families recognized in FRPS, i.e., Drynariaceae, Grammitidaceae, Gymnogrammitidaceae, Loxogrammaceae, Platyceriaceae, and Pleurosoriopsidaceae, all nest within the Polypodiaceae. Five lineages are defined that can be treated as subfamilies (see Christenhusz et al., Phytotaxa 19: 18-19. 2011) as follows: Loxogrammoideae (Loxogrammaceae): genus no. 1; Drynarioideae (Crypsinoideae, Drynariaceae, Gymnogrammitidaceae): genera nos. 2-8; Platycerioideae (Platyceriaceae, Pyrrosioideae): genera nos. 9-10; Microsoroideae (incl. Crypsinoideae, Lepisorioideae): genera nos. 11-25; Polypodioideae (incl. Grammitidaceae, Pleurosoriopsidaceae): genera nos. 26-39. The status of several genera in the Microsoroideae is controversial (Kreier et al., Molec. Phylogen. Evol. 48: 1155-1167. 2008). Microsorum is still polyphyletic, and some new genera are to be established.

Ching Ren-chang, Fu Shu-hsia, Wang Chu-hao & Shing Gung-hsia. 1959. Gymnogrammitis. In: Ching Ren-chang, ed., Fl. Reipubl. Popularis Sin. 2: 284-285; Wu Shiew-hung. 1999. Pleurosoriopsidaceae. In: Wu Shiew-hung, ed., Fl. Reipubl. Popularis Sin. 4(2): 154-156; Lin Youxing, Lu Shugang & Shi Lei. 2000. Polypodiaceae. In: Lin Youxing, ed., Fl. Reipubl. Popularis Sin. 6(2): 7-266, 346-349; Zhang Xianchun. 2000. Drynariacae, Platyceriaceae, Grammitidaceae, and Loxogrammaceae. In: Lin Youxing, ed., Fl. Reipubl. Popularis Sin. 6(2): 267-335.

More than 50 genera and ca. 1,200 species: pantropical, a few temperate; 39 genera and 267 species (82 endemic) in China.

(Authors: Zhang Xianchun (张宪春), Lu Shugang (陆树刚), Lin Youxing (林尤兴), Qi Xinping (齐新萍), Shannjye Moore (牟善杰), Xing Fuwu (邢福武), Wang Faguo (王发国); Peter H. Hovenkamp, Michael G. Gilbert, Hans P. Nooteboom, Barbara S. Parris, Christopher Haufler, Masahiro Kato, Alan R. Smith)