作者

HUANG, TSENG-CHIENG

型態特徵

Herbs, shrubs or trees; branches often quadrangular. Leaves opposite or whorled, seldom altenate, entire; stipules 0. Flowers bisexual, regular or rarely irregular, mostly axillary, solitary or in cymes or panicles; calyx-tube free, persistent, the lobes 3–6, valvate, often with accessory lobes; petals as many as calyx-lobes and inserted at the mouth of calyx, imbricate, or rarely 0; stamens few or many, inserted on the calyx; ovary superior, sessile or stalked, 2–6- or rarely 1-celled, with many, seldom few, ovules in each cell; style simple, the stigma capitate, rarely 2-lobed. Fruit a dehiscent or indehiscent capsule, free or adnate to the base of calyx, 2–6-celled or 1-celled by the imperfection of the partitions; seeds many, various in shape; endosperm 0; embryo straight.

屬

More than 20 genera, widely distributed but most abundant in tropical America; five genera in Taiwan.

參考文獻

作者

HSIEH, CHANG-FU

型態特徵

Aquatic floating herbs. Emerged leaves rosulate, rhombic to ovate-rhombic, coarsely dentate towards apex, the petioles inflated above the middle; submerged leaves opposite, pinnatisect. Flowers bisexual, axillary, solitary, pedicelled; calyx-tube short, adnate to the lower part of ovary, the limb 4-lobed, the segments often persistent and turning into horns after anthesis; petals 4, free; stamens 4, anther oblong, 2-locular, dehiscing logitudinally; ovary half-inferior, with a conical apex, 2-celled; ovule 1 in each cell. Fruit bony, in¬dehiscent, 1-seeded, with 2–4 horns; cotyledons very unequal.

參考文獻