Herbs, subshrubs, or shrubs [trees], annual or perennial, monoecious or dioecious; hairs stellate or scalelike; latex colorless to reddish [absent]. Leaves persistent, semideciduous, or drought deciduous, alternate, simple, often with lemony, pungent, or acrid odor when crushed, older leaves often turning orange before falling; stipules absent or present, persistent, deciduous, or caducous; petiole present [absent], glands present at apex or absent; blade unlobed [palmately lobed], margins entire, crenate, denticulate, serrulate, or serrate-dentate, laminar glands absent [at base, on margins or abaxial surface]; venation pinnate or palmate at base, pinnate distally. Inflorescences unisexual or bisexual (pistillate flowers proximal, staminate distal), terminal or axillary, spikes, racemes, or thyrses; glands subtending each bract 0. Pedicels present or absent. Staminate flowers: sepals (3–)5(–6), valvate or slightly imbricate, distinct or connate basally; petals (3–)5(–6) or 0, distinct, white; nectary extrastaminal, usually 5 glands; stamens 3–35[–50], inflexed in bud, distinct; pistillode absent. Pistillate flowers: sepals [3–](4–)5(–9)[–10] or 0, imbricate or valvate, distinct (connate for 1/2+ length in C. argyranthemus); petals 5 (sometimes rudimentary) or 0, distinct or connate basally, white or pale green; nectary annular, 5 glands, or absent; pistil (1–)3-carpellate; styles (1–)3, distinct or connate basally, unbranched, 2-fid, or multifid. Fruits usually capsules (achenes in C. michauxii). Seeds ellipsoid, oblong, ovoid, globose, or lenticular; caruncle present. x = 8, 9, 10, 14.

Source: [
• 13
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CROTON L.

Por Grady L. Webster

Arboles, arbustos o hierbas, con tricomas, al menos en parte, estrellados o lepidotos, sin látex; plantas monoicas o raramente dioicas. Hojas alternas o subopuestas debajo de las inflorescencias terminales, simples, a veces palmadamente lobadas, pinnatinervias o palmatinervias; pecioladas, muy frecuentemente estipuladas, frecuentemente glandulares. Flores en racimos o espigas terminales o axilares; flores estaminadas con sépalos mayormente 5, imbricados o valvados, pétalos 5 o raramente ausentes, imbricados, disco entero o disecado, estambres mayormente 8–50, libres, filamentos inflexos en la yema, pistilodio ausente; flores pistiladas sésiles o pediceladas, sépalos mayormente 5–7, imbricados o valvados, enteros o dentados, pétalos 5 ó ausentes, disco generalmente entero o lobado, ovario 3-locular, 1 óvulo por lóculo, estilos libres o casi así, bífidos o bipartidos a multífidos. Fruto capsular; semillas carunculadas.

Género tropical y subtropical con ca 1000 especies, mejor representado en América; 28 especies se conocen en Nicaragua y 1 más se espera encontrar.

G.L. Webster. A provisional synopsis of the sections of the genus Croton (Euphorbiaceae). Taxon 42: 793–823. 1993.

Source: [
• 14
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Hierbas, arbustos o árboles, monoicos o (rara vez) dioicos, con indumento generalmente de tricomas simples, estrellados o escamiformes, la savia incolora o (más frecuente) coloreada (anaranjada o rojiza); estípulas ausentes o (más frecuente) presentes, pequeñas, usualmente deciduas. Hojas alternas, el pecíolo usualmente con glándulas en el ápice; lámina simple, lobulada o (mucho más frecuente) no lobulada, de otra forma entera o aserrada. Infls. terminales o axilares, bisexuales o (rara vez) unisexuales, espigadas o racemosas, a veces paniculadas o subcapitadas, usualmente con las fls. pistiladas (1 por nudo) proximales y las estaminadas (1–numerosas por nudo) distales, o ambas mezcladas en los nudos. Fls. estaminadas con disco anular o disecado; sépalos 4–6(–10), imbricados o valvados; pétalos 5 (ausentes en C. punctatus); estambres 8–50, los filamentos curvados en el botón; pistiloide ausente. Fls. pistiladas con disco entero o lobulado; sépalos 4–10, imbricados o valvados; pétalos 5 (a veces reducidos o ausentes); ovario (2)3-locular; óvulos 1 por lóculo; esti- los ± separados, una vez a muchas veces bífidos. Frs. capsulares; semillas lisas o levemente rugulosas, carunculadas.

Source: [
• 16
• 19
]. 

Trees or shrubs, rarely subshrubs, monoecious or more rarely dioecious; latex clear or reddish, often scanty or apparently absent; indumentum of stellate hairs and/or peltate scales. Leaves alternate, rarely opposite or nearly verticillate; stipules present or absent; petiole with or without apical paired glands; leaf blade simple, margin entire or denticulate, often with glands; venation pinnate or palmate. Inflorescences terminal or axillary, racemelike thyrses, often with proximal solitary female flowers and distal male flowers, often in clusters. Male flowers: sepals mostly 5, imbricate to valvate, free; petals 5, smaller or nearly equal to sepals; disk glandular, usually 5, and opposite sepals; stamens 10-20; filaments free, inflexed in bud; anthers muticous; pistillode absent. Female flowers: sepals 5, often narrower than in male, imbricate to reduplicate-valvate, persistent, sometimes accrescent; petals 5, smaller than in male, mostly reduced or obsolete; disk annular or dissected, receptacle often villous; ovary 3-locular; ovules 1 per locule; styles 3, longer and slender, free or nearly so, once to several times bifid. Fruit a capsule dehiscing into 3 2-valved cocci, more rarely ± indehiscent and fleshy, drupelike or berrylike. Seeds usually smooth, carunculate; testa crustaceous; endosperm copious, fleshy; cotyledon broad and flattened.

Source: [
• 17
]. 

Trees, shrubs, or herbs; monoecious or dioecious; stems usually with colored sap, the indumentum (at least in part) stellate or lepidote. Leaves alternate; petiolate (petioles often with glands near the top); stipulate (stipules sometimes obscure or obsolete); blades pinnately or palmately veined, sometimes lobed, entire or serrate. Inflorescences spicate-racemose (or sometimes paniculate or subcapitate), terminal or axillary; bisexual racemes mostly with 9 flowers solitary at proximal nodes, male 1-several at distal nodes (sometimes at same nodes with female). Staminate flowers with 4-6 imbricate or (most often) valvate calyx-lobes; disc entire or dis- sected; petals usually 5 (rarely absent); stamens mostly 8-50, free, the filaments inflexed in bud; pollen grains globose, inaperturate, clavate; pistillode absent. Pistillate flowers with 4-10 (mostly 5-7) imbricate or valvate calyx-lobes; disc usually entire, rarely dissected, sometimes with staminodia; petals 5, often reduced or absent; ovary of 3 (rarely 2) carpels, the ovules 1 per locule; the styles more or less free, once to repeatedly bifid or bipartite. Fruits capsular; seeds terete to compressed, dry, carunculate, endosperm present, the embryo with broad cotyledons.

Source: [
• 18
• 15
]. 

"Monoecious or dioecious; cal 5–7-lobed; pet mostly as many as and about equaling the sep in staminate fls, but reduced or wanting in pistillate fls; stamens (3–)8–20+, inflexed in bud; anthers elongate; disk present; ovary (2)3-locular, with 1 ovule per locule; styles distinct or nearly so, bifid or dissected; fr capsular; seeds (1–)3, carunculate; herbs, shrubs, or trees with stellate pubescence, the small fls borne chiefly in condensed, spike-like, terminal infls. 600+, cosmop.In addition to the following spp., the southwestern sp. C. lindheimerianus Scheele has been reported from Ill. It is a diffusely branched, monoecious annual with entire lvs and 3 styles, each bifid to the base."

Source: [
• 20
]. 

Inflorescences terminal, sometimes axillary, racemose or spicate, with the flowers sometimes in fascicles or glomerules on the spike, rarely paniculate, androgynous, with the ♀ flowers usually below the ♂’s, or unisexual; bracts small, caducous or persistent

Source: [
• 11
]. 

Male flowers: sepals (4–)5(–6), valvate or imbricate, ± equal; petals usually present, (4–)5(–6), rarely more, free, equalling or shorter than (rarely longer than) the sepals; disc-glands small, opposite the sepals, free or fused, fleshy, rarely 0; stamens central, 5–many, free, inserted on a usually pilose receptacle, the filaments inflexed in bud, later erect, the anthers pendulous in bud, later erect, longitudinally dehiscent; pistillode 0

Source: [
• 11
]. 

Seeds smooth or more rarely rugulose, generally triangular-convex in transverse section, carunculate, with a woody or crustaceous testa and abundant fleshy albumen; embryo straight; cotyledons broad and flat.

Source: [
• 11
]. 

Female flowers: sepals often narrower than in ♂, generally persistent and slightly accrescent, equal or unequal; petals often smaller and/or narrower than in ♂, or vestigial or 0, rarely replaced by tufts of hairs; staminodes sometimes present; disc annular or composed of separate glands, sometimes scarcely developed; ovary (2–)3(–4)-locular, with 1 ovule per locule; styles 1–several times bifid or bipartite, rarely laciniate

Source: [
• 11
]. 

Fruits dehiscent, septicidally into 3 bivalved cocci, or loculicidally into 3 valves, or sometimes drupaceous or berry-like, and then subindehiscent; endocarp woody or crustaceous

Source: [
• 11
]. 

Leaves alternate or sometimes subopposite or subverticillate on the same shoot, simple, entire or toothed, rarely lobed (not in E. Africa), penninerved or 3–many-nerved from the base, petiolate, usually with two (sometimes more) sessile or stalked discoid glands at the base of the blade, generally stipulate, often turning bright yellow or red when dying

Source: [
• 11
]. 

Monoecious or more rarely dioecious trees, shrubs or, more rarely, herbs or lianes, with an indumentum of stellate hairs or peltate scales, separately or in combination

Source: [
• 11
]. 

Inflorescences usually terminal, racemose, androgynous or unisexual; bracts small.

Source: [
• 12
]. 

Leaves alternate, sometimes subopposite or ± whorled, stipulate, petiolate, with 2 or more sessile or stipitate discoid glands at the petiole apex or the lamina base, simple, entire, toothed or lobed, penninerved or palminerved.

Source: [
• 12
]. 

Female flowers pedicellate; sepals generally persistent, slightly accrescent, equal or unequal; petals often smaller than in male flowers, sometimes replaced by tufts of hairs or absent; staminodes sometimes present; disk annular, or of separate glands, or vestigial; ovary 2(3)4-locular, with 1 ovule per loculus; styles 1–several times bifid or bipartite, or multifid or multipartite.

Source: [
• 12
]. 

Male flowers shortly pedicellate; buds subglobose; sepals (4)5(6), valvate or imbricate, ± equal; petals (4)5(6), free; disk glands opposite the sepals, free or fused, fleshy; stamens 5–many, free, filaments inflexed in bud, later erect, anthers pendulous in bud, later erect, longitudinally dehiscent; receptacle usually pilose; pistillode absent.

Source: [
• 12
]. 

Monoecious or sometimes dioecious trees or shrubs (or herbs or lianes outside the Flora Zambesiaca area) with a stellate and/or lepidote indumentum.

Source: [
• 12
]. 

Seeds carunculate; testa woody or crustaceous; albumen fleshy, copious; embryo straight; cotyledons broad and flat.

Source: [
• 12
]. 

Fruits septicidally dehiscent into 3 bivalved cocci, loculicidally dehiscent into 3 valves, irregularly frangent (breaking up) or drupaceous and indehiscent; endocarp woody or crustaceous.

Source: [
• 12
]. 

Trees, shrubs, or herbs

Source: [
• 18
• 15
]. 

Nearly 1000 species have been described in this natural but polymorphic genus. The majority of the species are American, but most of these occur in South America and the West Indies; about 80 distinct species have been recognized in continental North America.

Source: [
• 18
• 15
]. 

SELECTED REFERENCES Berry, P. E. et al. 2005. Molecular phylogenetics of the giant genus Croton (Euphorbiaceae sensu stricto) using ITS and trnL–F DNA sequence data. Amer. J. Bot. 92: 1520–1534. Ferguson, A. M. 1901. Crotons of the United States. Rep. (Annual) Missouri Bot. Gard. 1901: 33–73. van Ee, B. W. and P. E. Berry. 2010. Taxonomy and phylogeny of Croton section Heptallon (Euphorbiaceae). Syst. Bot. 35: 151–167. van Ee, B. W. and P. E. Berry. 2009. The circumscription of Croton section Crotonopsis (Euphorbiaceae), a North American endemic. Harvard Pap. Bot. 14: 61–70. van Ee, B. W., R. Riina, and P. E. Berry. 2011. A revised infrageneric classification and molecular phylogeny of New World Croton (Euphorbiaceae). Taxon 60: 791–823. Webster, G. L. 1993. A provisional synopsis of the sections of the genus Croton (Euphorbiaceae). Taxon 42: 793–823.

Source: [
• 13
].