特徵描述
作者
YANG, Yuen-Po and LU, Sheng-You
型態特徵
Trees or erect or scandent shrubs or climbers, polygamous or dioecious, evergreen or deciduous. Leaves usually opposite, simple, trifoliolate or pinnate, entire or toothed, estipulate. Inflorescence terminal or axillary, cymose or thyrsoid or dichasial. Flowers actinomorphic, perfect or unisexual; calyx small, 4-lobed or 4-parted; corolla sympetalous, 4-lobed or rarely 6–9-lobed, lobes imbricate or valvate in bud, sometimes almost free, rarely reduced; stamens usually 2, epipetalous, longitudinally dehiscent; ovary superior, 2-celled, ovules usually 2, apical or basal in each cell, style simple, terminal with a simple or 2-lobed stigma. Fruit a drupe, berry, capsule or samara; seeds with a large straight embryo, with or without endosperm.
屬
A worldwide, woody family with about 28 genera and more than 400 species in temperate and tropical regions. Five genera in Taiwan.
參考文獻
Fraxinus 梣屬
作者
YANG, Yuen-Po and LU, Sheng-You
型態特徵
Deciduous trees. Leaves opposite, odd-pinnate, leaflets serrate or entire. Inflorescence thyrsoid, bracteate, bracts caducous. Flowers small, perfect or unisexual; calyx small, 4-toothed or wanting; corolla usually deeply 4-lobed, lobes valvate in bud; stamens 2, inserted near base of corolla lobes, filaments short or long; ovary 2-celled, style short, stigma 2-lobed; ovules 2 in each cell. Fruit a samara, 1-seeded, indehiscent; seeds oblong, flattened, pendulous, with fleshy endosperm.
