特徵描述
作者
LI, HUI-LIN and LO, HANN-CHUNG
型態特徵
Erect or prostrate, rarely scandent, herbs or shrubs, or trees (sometimes deciduous), with stellate hairs or scales, occasionally (partly) aculeate, without milky latex. Trees usually with prominent plank buttresses, crown generally with only a small number of orders of branching. Leaves spirally arranged or distichous, occasionally subopposite, simple, rarelypalmately compound, usually lepidote- or stellate-hairy, mostly pinnately nerved above basal nervation, very rarely entirely pinnately nerved; stalk often long and kneed; stipules free, mostly caducous. Flowers small to medium in size, in axils of leaves or fallen leaves, extra axillary (not rarely leaf opposed), cauliflorous, ramiflorous or terminal, mostly in cymes (very often combined into aggregates), clusters, heads, racemes, spikes, umbels, panicles or corymbs, sometimes solitary or boragoid, mostly dichlamydeous, actinomorphic (to zygomorphic), mostly bisexual, or by abortion unisexual, monoecious or polygamo-monoecious, subtended by bracts and/or bracteoles, or not so (bracts sometimes forming an epicalyx); receptacle usually not enlarged, sometimes forming a gynandrophore; disk present or absent; calyx connate, rarely almost free, occasionally bilabiate; lobes 3–8, often 5, rarely 2, valvate; petals free or basally adnate to androecium, 5 or 0, not rarely (partly)reduced, or asymmetric, (sinistrorsely or dextrorsely) contorted, sometimes clawed; androecium extraordinarily variable in structure; stamens 2-seriate, (4-)5, 10, 15-many, usually the oppositisepalous ones (rarely the oppostipetalous ones) fertile; filamens mostly obvious, free or usually fascicled (fascicles 1 to several, each bearing one or several stalked or sessile anthers; degree of concrescence of filaments different, upper margin of variable structure), androphore sometimes present; anthers 2–3-celled; cells sometimes confluent, mostly longitudinally dehiscent, rarely poricidal; staminodes absent or present, sometimes petaloid, occasionally a few together; gynoecium syncarp to apocarp (carpels entirely free, each with distinct style, to entirely connate, with 1 style; in intermediate cases the carpels are shortly basally connate, or free as is lower part of style; upper part of style, however, connate), sessile or sometimes on a stalk which may be fused to stamen column (androgynophore), ovary superior, in staminate flower reduced, 1–5(–12)-celled; ovules 2-many, rarely 1 in each cell; placenta axile; styles 1–6, free to connate; heterostyly observed; stigma entire, radiate or penicillate; pistillode present or absent; fruit various, dehiscent or indehiscent, dry or fleshy, mostly woody or coriaceous, smooth orarmed, mostly capsular (loculicidally, sometimes septicidally 5) valved, rarely combination of both modes), drupaceous or the carpels splitting into sessile or stalked, dehiscent or indehiscent, sometimes samaroid mericarps, 1-several-celled; seeds 1-many, alate or exalate; embryo curved or straight; sarcotesta sometimes present; endosperm copious or scanty or 0.
屬
About 60 genera, up to 1,000 species, widespread in the tropics and subtropics, rare in temperate regions.
參考文獻
Pterospermum 翅子樹屬
作者
LI, HUI-LIN and LO, HANN-CHUNG
型態特徵
Stellately pubescent, inermous trees or erect shrubs, often with suckers; crown usually becoming somewhat flattened; bole with short buttresses, with short depressions cell all over, occasionally fluted; bark pale brown, smooth to shallow fissured or slightly scaly; twigs, buds and stipules densely tomentose. Leaves distichous, simple, entire or variously lobed, oblique at base, frequently peltate in young trees, densely soft-hairy beneath, palmately nerved, tertiary nerves ladder-like; petiole very short; stipules entire or divided. Flowers mostly axillary, solitary or in few flowered fascicles or cymes, sometimes in short terminal racemes, generally large, showy, bud narrowly cylindrical, 5-merous, bisexual; bracts entire or laciniate; sepals shortly connate or nearly free, coherent or not, linear, fleshy, sometimes abscissing at the base and remaining as a loose collar around the ripened fruit; petals white or yellow, turning brown, wavy, strap-shaped, imbricate, like calyx falling off after anthesis; recepacle raised to (short) gynandrophore; disk absent; stamens 15, in 5 bundles of 3 each, linear filiform, anthers narrowly long, cells 2, parallel, connective prolonged; staminodes 5, linear subulate, alternating with stamen bundles, opposite to petals; ovary densely tomentose, 5-celled, many-ovuled; style filiform; stigma widened, entire or obscurely grooved. Capsule oblong, large, glabrescent or persistently tomentose, woody, loculicidally 5-valved, stalked. seeds many, flattened, subglabrous, bearing a long wing on one side of apex.
