特徵描述
作者
YANG, Yuen-Po
型態特徵
Annual or perennial dioecious or polygamous fresh or saltwater herbs. Leaves radical or cauline, alternate, opposite or whorled, linear, lanceolate, elliptic or cordate, sessile or petiolate; petioles usually sheathing. Axillary scales present, 2-numerous. Flowers actinomorphic, unisexual or bisexual, enclosed in a bifid spathe or within two opposite bracts. Spathes sessile or long pedicellate. Sepals 3, valvate, green; petals 3, sometimes reduced to 2, imbricate, colored, or absent. Stamens 3-many; anthers 2-celled, longitudinally dehiscent; filaments slender. Ovary inferior, apex sometimes beaked, 1- or incompletely many-celled, parietal placenta protruding nearly to the center of ovary; styles mostly united, stigmas entire or bifid; ovules numerous. Fruit linear or ovoid, irregularly dehiscent. Seeds numerous, filiform or ovate; testa glabrous or echinate; endosperm absent; embryo straight.
屬
Sixteen genera, about one hundred species, tropical and temperate; seven genera in Taiwan.
參考文獻
Vallisneria 苦草屬
作者
YANG, Yuen-Po
型態特徵
Submersed, dioecious, stoloniferous perennials without stems. Leaves radical, linear, ribbon-like, serrulate, sheathing at base. Flowers unisexual, pedunculate. Staminate spathes small, ovoid, peduncle short. Staminate flowers small, numerous, pedicellate, detaching from spathe and floating free before anthesis; sepals 3, ovate, convex; petals 3; stamens 1-3. Pistillate spathes cylindrical, bifid, pedunculate; peduncles elongate, coiled after anthesis; pistillate flower 1 per spathe; sepals 3, ovate; petals 3, ovate, much smaller than sepals; ovary inferior, linear, nodose; styles 3, bifid. Fruit linear. Seeds numerous, filiform.
