Herbs, subshrubs, shrubs, or trees, usually stellate-hairy. Leaves alternate, usually spiral, sometimes distichous (Malvoideae), usually petiolate, sometimes subsessile or sessile (Malvoideae), stipulate (usually well developed), simple (compound in Abelmoschus); blade unlobed or palmately lobed, palmately veined. Inflorescences axillary, terminal, or leaf-opposed. Flowers bisexual or unisexual, usually actinomorphic; involucel (epicalyx) sometimes deciduous (Malvoideae, Sterculioideae), (4–)5(–8), distinct or connate; petals 4 or 5 (absent in Bombacoideae and Sterculioideae, rarely absent in Grewioideae); nectaries glandular hairs on adaxial base of sepals, petals, or androgynophores, sometimes absent; androgynophore present or absent; stamens [4–]5–100[–1500], usually in antipetalous groups; usually same number as sepals, distinct or connate, sessile or on androgynophore; ovules (1–)2–many per ovary. Fruits usually capsules, sometimes follicles, schizocarps, berries, or nuts. Seeds: cotyledons usually folded, endosperm absent or sparse to copious.
Herbs, shrubs, or less often trees; indumentum usually with peltate scales or stellate hairs. Leaves alternate, stipulate, petiolate; leaf blade usually palmately veined, entire or various lobed. Flowers solitary, less often in small cymes or clusters, axillary or subterminal, often aggregated into terminal racemes or panicles, usually conspicuous, actinomorphic, usually bisexual (unisexual in Kydia). Epicalyx often present, forming an involucre around calyx, 3- to many lobed. Sepals 5, valvate, free or connate. Petals 5, free, contorted, or imbricate, basally adnate to base of filament tube. Stamens usually very many, filaments connate into tube; anthers 1-celled. Pollen spiny. Ovary superior, with 2-25 carpels, often separating from one another and from axis; ovules 1 to many per locule; style as many or 2 × as many as pistils, apex branched or capitate. Fruit a loculicidal capsule or a schizocarp, separating into individual mericarps, rarely berrylike when mature (Malvaviscus); carpels sometimes with an endoglossum (a crosswise projection from back wall of carpel to make it almost completely septate. Seeds often reniform, glabrous or hairy, sometimes conspicuously so.
Fruit a capsule or breaking into separate compartments
Stamens numerous, monadelphous; anthers 1-celled
Ovary syncarpous, rarely of 1 carpel, rarely the carpels in vertical rows; style one
Petals 5, free from each other but often adnate at the base to the staminal column, contorted or imbricate
Flowers actinomorphic, hermaphrodite or rarely unisexual
Sepals valvate, with or without an epicalyx of bracteoles
Seeds usually with some endosperm and straight or curved embryo, the cotyledons often folded
Herbs often with fibrous stems or rarely shrubs; hairs usually stellate or lepidote
Leaves alternate, often palmately nerved or divided; stipules present
Calyx (3–4) 5-lobed, truncate or occasionally 5- or 10-toothed; lobes valvate
Petals 5, free but often slightly adnate to the staminal tube, contorted or imbricate
Flowers bisexual (rarely unisexual), actinomorphic
Seeds usually with some endosperm; cotyledons often folded
Leaves alternate, usually petiolate, often palmately divided
Herbs, shrublets, shrubs or small trees, usually with stellate hairs or bristles, sometimes aculeate, more rarely lepidote
Stamens numerous, united in, a tube surrounding the style; anthers 1-thecous
Ovary superior, (1) 2-multilocular (carpels rarely in vertical rows); style simple at the base, often branched towards the apex, branches the same number as or twice as many as the carpels; ovules 1-numerous in each loculus; placentation axile
SELECTED REFERENCES Bayer, C. et al. 1999. Support for an expanded family concept of Malvaceae with a recircumscribed order Malvales: A combined analysis of plastid atpB and rbcL DNA sequences. Bot. J. Linn. Soc. 129: 267–303. Bayer, C. and K. Kubitzki. 2003. Malvaceae. In: K. Kubitzki et al., eds. 1990+. The Families and Genera of Vascular Plants. 10+ vols. Berlin etc. Vol. 5, pp. 225–311. Brizicky, G. K. 1966. The genera of Sterculiaceae in the southeastern United States. J. Arnold Arbor. 47: 60–74. Judd, W. S. and S. R. Manchester. 1997. Circumscription of Malvaceae (Malvales) as determined by a preliminary cladistic analysis of morphological, anatomical, palynological, and chemical characters. Brittonia 49: 348–405. Whetstone, R. D. 1983. The Sterculiaceae in the flora of the southeastern United States. Sida 10: 15–23.