Thymelaeaceae

Abstract

Trees, shrubs, lianas, or rarely herbs, evergreen or deciduous, usually poisonous, often with intraxylary phloem, more rarely also with interxylary phloem. Leaves alternate or opposite, petiolate or sessile, simple, entire, exstipulate; secondary veins occasionally terminating in a marginal vein. Inflorescences usually indeterminate or rarely with terminal flowers; bracts often forming an involucrum, rarely completely reduced. Flowers hermaphroditic or unisexual; floral tube usually present, often conspicuously coloured, short and cupular in Octolepidoideae and extended in Thymelaeoideae, occasionally articulated above ovary, deciduous or fully to partly persistent in fruit; sepals (3)4–5(6), imbricate or more rarely valvate; petals either fully developed or strongly to totally reduced, as many as, twice as many as, or even more than twice as many as sepals, sometimes united below or fused to form an annulus, inserted on rim of the floral tube, the upper portion of floral tube, or at receptacle; androecium diplostemonous, haplostemonous, polystemonous, or stamens rarely 2 or 1, in Thymelaeoideae inserted in upper portion of floral tube (except Synandrodaphne) and in Octolepidoideae at receptacle; antesepalous stamens sometimes adnate to base of sepals; filaments long, short, or anthers sessile, rarely fused to form a tube; anthers straight, reflexed, peltate or horseshoe-shaped, usually 4-sporangiate, introrse or rarely extrorse, basifixed or rarely dorsifixed; floral disk variable in shape or absent; ovary in Octolepidoideae 3–12-locular, in Thymelaeoideae 1- or 2-locular, sometimes stiped, glabrous to pubescent; ovules anatropous, axile, 1 per locule; style present or very rarely absent, inserted terminally or laterally on ovary; stigma often papillose; carpels sometimes provided with dorsal effigurations (“parastyles”). Fruit a loculicidal capsule with up to 9 locules, or indehiscent, 1(2)-locular; seeds 1 per locule, with or without aril-like appendix arising from chalaza or raphe; seed coat glabrous or in taxa with dehiscent fruits often pubescent, crustaceous or more rarely membranous; cells of inner epidermis usually with stripes on inner surface; endosperm copious to absent; cotyledons thick or thin; radicle very short or rarely elongated.