找植物
找標本
電子書

Sterculiaceae

梧桐科

特徵描述
屬列表
標本列表

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.

About 60 genera, up to 1,000 species, widespread in the tropics and subtropics, rare in temperate regions.

參考文獻

Firmiana 梧桐屬

作者

LI, HUI-LIN and LO, HANN-CHUNG

型態特徵

Inermous trees or erect shrubs. Leaves spirally arranged, simple, entire or palmately lobed, frequently trilobed especially when young, base heart-shaped, palmately nerved; stipules small. Flowers in axils of fallen leaves, in panicles or racemes, bisexual in appearance but apparently one sex sterile, monoecious, brilliantly coloured, stellate-hairy; calyx tubular-clavate, 5-dentate to connate at base, sepals 5, free, coloured; corolla absent; gynandrophore short or long; disk coating base of calyx-tube; staminate flower: gynandrophore very long, crowned by 15 capitate sessile, 2-celled anthers; pistillodes 5, hidden by anthers; pistilate flower: staminal tube bearing at apex a ring of 12–15 anthers; carpels 5, 2-celled, separating after anthesis; 2–4 ovules in each cell; styles short, more or less excentric; stigma recurved; follicles free, stalked, papery, entirely dehiscing long time before maturity, bearing in lower half along each margin 1 (or more) cross-oval seeds, dispersed with adhering seed; seeds exalate.

參考文獻

標本列表