7. Psilotaceae
松叶蕨科 song ye jue ke
Authors: Li-Bing Zhang & George Yatskievych
Plants small to medium-sized, epiphytic or on rocks. Rhizomes creeping, brown, with protostele or siphonostele, bearing rhizoids; roots absent. Stems erect or pendulous, green, unbranched or dichotomously or pinnately branched; branches ridged to sulcate or complanate. Leaves small or rudimentary, with a single vein (microphylls) or lacking veins (enations), spirally or distichously alternate, sessile or subsessile, dimorphic; trophophylls scalelike and subulate-triangular, or lanceolate to narrowly ovate; sporophylls deeply bifid. Sporangia appearing solitary at or above bases of sporophylls, large, 2- or 3-lobed (sometimes interpreted as synangia of 2 or 3 unlobed sporangia), thick-walled, lacking an annulus, each lobe dehiscing longitudinally by a slit. Spores reniform, monolete, many (> 1000) per sporangium, exospore translucent, rugulate to foveolate. Gametophytes subterranean (Psilotum), non-photosynthetic, cylindrical, mycorrhizal. x = 52.
Two genera (Psilotum, Tmesipteris) and ca. 17 species: tropics to temperate regions; one species in China.
Zhang Libing. 2004. Psilotaceae. In: Zhang Xianchun, ed., Fl. Reipubl. Popularis Sin. 6(3): 244-245.
