Cyatheaceae
桫欏科
特徵描述
作者
SHIEH, WANG-CHUENG
型態特徵
Mostly tree ferns with massive, tall, erect, usually unbranched stems, the lower part of trunk usually covered with interlacing roots (a few species have short prostrate rhizome), dictyostelic. Fronds often very large, arranged in a terminal crown, bi-tripinnatifid (one genus pinnate); veins usually free, forked (one genus anastomosing); stipes persistent or caducous, hairy and (or) scaly; stipes scales conform (setiferous) i.e. with all cells in parallel rows, or marginate (flabelloid)i.e. with marginal cells oriented differently than central ones; leaf-scar pattern usually with 3-series of small vascular bundles; aerophores borne along side of stipe, occuring as streaks arranged in 1 to 3 lines (not so obvious on dried specimens as on living plants). Sori round, borne on backs of veins, with or without indusia; indusia of various shapes; sporangia ovoid, with a complete oblique annulus (i.e. not interrupted at the stalk), stalk long or short, paraphyses present. Spores trilete.
屬
Four genera, with about 800 species, one genus in Taiwan.