特徵描述
作者
LI, HUI-LIN
型態特徵
Trees or shrubs, almost always with bitter bark. Leaves alternate, often very large, pinnate or rarely simple; stipules 0 or deciduous. Inflorescence axillary, racemose, paniculate or cymose, rarely spicate. Flowers usually diclinous, regular, and generally small. Calyx 3–5-lobed, valvate or imbricate. Petals 3–5, very rarely 0, hypogynous, valvate or imbricate. Disc annular or elongate, simple or lobed, rarely 0. Stamens as many or twice as many as the petals, rarely indefinite, inserted at the base of the disc; filaments free, often with a scale at the base; anthers oblong, usually introrse, 2-celled, dehiscing longitudinally. Ovary free, 1–6-celled, usually deeply lobed, or entire; styles 2–5, free or more or less united, the stigmas capitate; ovules solitary in each cell, rarely numerous, the raphe ventral, the micropyle superior. Fruit drupaceous, capsular, or occasionally samaroid, usually of 2–6 distinct carpels. Seeds usually solitary, erect or pendulous, albuminous; embryo straight or curved, radicle superior.
屬
About 30 genera and 150 species, in tropical and subtropical regions of both hemispheres; three genera in Taiwan.
參考文獻
Ailanthus 樗屬
作者
LI, HUI-LIN
型態特徵
Large trees. Leaves very large, alternate, unequally pinnate. Flowers small, polygamous, bracteolate, in terminal or axillary panicles; calyx 5-fid, the lobes equal, imbricate; petals 5, valvate; disc 10-lobed; stamens 10 in hermaphroditic flowers (2–3), the filaments short or filiform, without scales; ovary 2–5-partite, the styles connate; ovules 1 in each cell, semi-anatropous. Fruit of 1–5 1-seeded samaras; wing very large, membranaceous. Seeds pendulous, sparingly albuminous.
