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
Hydrocharis 水鱉屬
作者
YANG, Yuen-Po
型態特徵
Submersed freshwater herbs with elongate leafy stems. Leaves floating or emergent, rounded or reniform, broadly acute or rounded, long petiolate, veins curving, joining at apex; petiole stipulate, stipules membranaceous. Staminate flowers 2 or 3 per spathe, short pedicellate; sepals 3, elliptic, white or greenish white, persistent; petals 3, larger than sepals, broadly ovate; stamens 6-18; anthers laterally dehiscent. Female flowers solitary, pedicellate; sepals 3, elliptic; petals 3, broadly ovate; staminodes 6; ovary ovoid, 6-celled; styles 6, linear, bifid. Fruit ovoid. Seeds numerous, ellipsoid.
