5. PTERIDACEAE subfam. VITTARIOIDEAE
书带蕨亚科 shu dai jue ya ke
Authors: Youxing Lin, Zhang Xianchun, Michael G. Gilbert & Jefferson Prado
Plants terrestrial, epiphytic, or epilithic, medium-sized or small. Rhizome creeping or short and erect, siphonostelic, bearing roots with very numerous water-absorbing root hairs, scaly; scales brown or black, sometimes clathrate and iridescent. Fronds monomorphic, clustered to widely scattered; stipe well defined, dark, often glossy, or ill defined and merging with lamina, lamina entire or 1-3- or more pinnate or 1-3-dichotomous with pedate branches, herbaceous, papery, leathery, or less often membranous or fleshy; pinnules sometimes with articulate stalk, ovate, flabellate, orbicular-flabellate, or dimidiate, often glabrous, epidermis sometimes with large elongate siliceous cells, veins free, reaching margins, or anastomosing, simple or dichotomously forked, often radiate. Sori elongate along fertile veins, usually immersed in grooves, on veins of recurved, membranous false indusium, often with abundant paraphyses. Spores transparent, mostly ellipsoid, sometimes fusiform, or tetrahedral-globose, trilete or monolete.
Eleven genera and ca. ?300 species: pantropical; four genera and 58 species (17 endemic) in China.
Molecular data have shown that Vittariaceae and Adiantaceae form a well-defined monophyletic group, Vittarioideae, within the Pteridaceae.
rbcL gene analysis by Crane (Syst. Bot. 22: 509-517. 1997) indicated that the traditional Antrophyum and Vittaria Smith are both polyphyletic or paraphyletic. Ten monophyletic genera are recognized in Vittariaceae, i.e., Ananthacorus Underwood & Maxon, Anetium Splitgerber, Antrophyum, Haplopteris, Hecistopteris J. Smith, Monogramma, Polytaenium Desvaux, Radiovittaria (Benedict) E. H. Crane, Scoliosorus T. Moore, and Vittaria. Only Antrophyum, Haplopteris, and Monogramma are distributed in China. All the Chinese species formerly classified in Vittaria are now treated in Haplopteris.