Herbs, subshrubs, shrubs, trees, or vines [lianas], annual, biennial, or perennial, deciduous or evergreen, monoecious or dioecious; latex present or absent. Leaves alternate, opposite, whorled, or fascicled on short shoots, simple (3-foliolate in Tragia laciniata) [palmately compound]; stipules present or absent; petiole present or absent; blade sometimes palmately lobed, margins entire, subentire, repand, crenate, serrate, or dentate; venation pinnate, palmate, or palmate at base and pinnate distally. Inflorescences unisexual or bisexual, axillary, terminal, or leaf-opposed [cauliflorous], racemes, panicles, spikes, thyrses, cymes, fascicles, or pseudanthia, or flowers solitary. Flowers unisexual; perianth hypogynous; hypanthium absent; sepals 0 or 2–12, distinct or connate basally to most of length; petals 0 or (3–)5(–6), distinct or connate; nectary present or absent; stamens 1–35(–1000), distinct or connate, free; anthers dehiscing by longitudinal slits; pistil 1, (1–)3–5(–20)-carpellate, ovary superior, (1–)3–5(–20)-locular, placentation axile; ovules 1 per locule, anatropous; styles 1–5(–9), distinct or connate, unbranched, 2-fid, or multifid; stigmas 1–32+. Fruits usually capsules, dehiscence septicidal, (usually schizocarpic with cocci separating from persistent columnella, coccus usually dehiscent loculicidally), sometimes schizocarps, drupes, or achenes [berries]. Seeds 1 per locule.
Trees, shrubs, or herbs, rarely woody or herbaceous lianas, monoecious or dioecious, indumentum of simple, branched, stellate, or gland-tipped hairs, peltate or glandular scales or stinging hairs, latex often present, clear, white, or colored; roots woody, rarely roots tuberous and stems succulent, sometimes spiny. Leaves alternate or opposite, rarely whorled; stipules usually present, often free, sometimes modified into spines or glands, deciduous or persistent; petioles long to short, sometimes with glands at apex or base; leaf blade simple, sometimes palmately lobed, rarely compound, or reduced to scales, margins entire or toothed, sometimes with distinct glands along margin and/or on surface, venation pinnate or palmate. Inflorescences axillary or terminal, flowers in cymes or fascicles, these often arranged along an elongated axis, branched or unbranched, forming a thyrse, in congested heads, or in a flowerlike cyathium with very reduced flowers enclosed within a ± cupular involucre; bracts sometimes petaloid. Flowers unisexual, within same inflorescence or in separate inflorescences, actinomorphic. Sepals (1-)3-6(-8), free or connate into calyx tube, valvate or imbricate, rarely absent (Euphorbia). Petals free, often reduced or absent. Disk present or absent. Male flowers with disk intrastaminal or extrastaminal, entire to dissected. Stamens one to very many, hypogynous; filaments free or connate; anthers 2(-4)-locular, mostly dehiscing longitudinally, rarely transversely or by pores, introrse or extrorse; rudimentary ovary sometimes present. Female flowers rarely with staminodes; ovary superior, (1-)2-5(-20)-locular; placentation axile; ovules 1 or 2 per locule, anatropous or hemitropous; styles free or connate, entire or lobed, or multifid, lobes erect, horizontal or curved; stigma capitate, linear, fimbriate, fan-shaped or pinnatilobate. Fruit typically a capsule elastically dehiscent into 2-valved cocci from a persistent columella, sometimes a berry or drupe. Seeds 1 or 2 per locule; seed coat thin to indurate, sometimes fleshy to form a sarcotesta; caruncle sometimes present; aril sometimes present; endosperm present or absent; embryo straight to curved or folded; cotyledons usually broader than radical. x = 6-14.
Trees, shrubs, or herbs, usually without latex (present in Bischofia); indumentum of simple hairs (branched in Phyllanthus reticulatus), often absent. Leaves alternate, often distichous, sometimes scalelike on main stems; petiole usually short, usually without glands (present in Aporosa); leaf blade simple, margin entire or minutely serrulate (long petioles, 3(-5)-foliolate with toothed margins in Bischofia); venation pinnate, rarely obscurely 3-veined from base. Inflorescences mostly axillary, without visible axis (present in Antidesma, Aporosa, Baccaurea, Bischofia, Richeriella). Male flowers with 2-8 stamens, anthers longitudinally dehiscent (variable in Phyllanthus); female flowers with 2 ovules per locule. Seeds without caruncle, sometimes with fleshy aril or fleshy testa.
Trees to shrubs. Leaf blade leathery, grayish when dry, base often asymmetrical. Ovules 1 per locule; stigmas dilated, peltate or reniform. Fruit a relatively large 1-seeded drupe, usually crowned by persistent flaplike stigmas. Seeds without caruncle.
Plants with or without latex; indumentum of simple, stellate, scalelike, stinging, or glandular hairs, sometimes absent. Leaves alternate or opposite; leaf blade simple or compound, sometimes deeply divided, margin entire or variously toothed, often with sessile glands near junction with petiole and/or along margins; venation pinnate or palmate. Inflorescences basically thyrsoid, very variable, often with well-defined main axis and/or distinct cymes, rarely a sessile axillary fascicle. Ovules 1 per locule of ovary. Seed sometimes carunculate, sometimes arillate.
Trees, shrubs or herbs, occasionally with milky juice
Seeds often with a conspicuous caruncle; endosperm copious, fleshy; embryo straight
Leaves alternate or rarely opposite, simple or digitately compound, sometimes reduced, mostly stipulate
Flowers unisexual, mostly monoecious
Sepals imbricate or valvate, or in very specialized inflorescences much reduced or absent
Petals absent or rarely present and sometimes united
Stamens 1–1, 000, free or variously connate; anthers 2–4-celled, erect or inflexed in bud, opening lengthwise, rarely by pores
Rudimentary ovary often present in the male flowers
Ovary mostly 3-celled; styles free or united at the base; ovules solitary or paired, pendulous from the inner angle of the cells
Seeds 1–2 per locule, or by abortion solitary in the fruits, attached near or above the middle of the locule, carunculate or not, often myrmecochorous; testa crustaceous to osseous; endosperm usually copious and fleshy, rarely 0; embryo straight, extending for most of the length of the seed; radicle superior; cotyledons usually broad and flat, rarely thick and fleshy or folded
Stipules free or connate, sometimes spathaceous, membranaceous, capilliform, glandular or spiny, subpersistent to readily caducous or 0
Leaves usually alternate, sometimes opposite, rarely whorled, occasionally all three, green or scarious and squamiform, commonly petiolate, sometimes sessile, stipulate or exstipulate, simple, lobed or compound, entire or variously toothed, peltate or not, palminerved or penninerved, often with a pair — sometimes with several pairs — of basal glands at or near the petiole-insertion, and/or minutely pellucid-glandular-punctate beneath
Dioecious or monoecious often poisonous prostrate, erect or scandent annual, biennial or perennial herbs, shrubs or trees, with the stems succulent or not, spiny or unarmed, sometimes with phylloclades, with or without a milky latex or coloured sap; indumentum 0 or of simple, branched or stellate hairs or peltate scales, the hairs sometimes urticating
Calyx in both sexes usually of 3–6-valvate, imbricate or open equal or unequal lobes or free sepals, often dissimilar between the two sexes, rarely the ? calyx spathaceous, sometimes accrescent, minute or 0
Flowers unisexual, usually actinomorphic and small to minute
Disc in the ? flowers of 5–6 or occasionally more free extrastaminal and/or intrastaminal glands, rarely the disc annular or cupular and extrastaminal or lobate and central, or else the disc receptacular, domed and aperturate with the stamens arising through the apertures, or disc 0; in the ? flowers hypogynous, annular and flat or cupular, entire or lobate, rarely of separate glands, or 0
Corolla in one or both sexes of 3–6 free or rarely united subvalvate or imbricate petals, or petals minute or 0
Inflorescences terminal, axillary, lateral or leaf-opposed, cymose, paniculate, racemose or spicate, or with the flowers aggregated into involucrate pseudanthia, as in the glanduliferous cyathia of the Euphorbieae, which may themselves be aggregated into pseudopleiochasial super-inflorescences, or else with the flowers fasciculate or solitary in the leaf-axils
Fruit usually schizocarpic, dehiscing septifragally and septicidally into 1–4(–20) (but usually 3) bivalved cocci leaving a persistent winged or angled columella, the valves then opening ventrally to allow the seeds to escape, or else the fruit loculicidally dehiscent, usually into 3 septate valves, or all three modes of dehiscence present and ± simultaneous, or else the fruit indehiscent, drupaceous or subdrupaceous, with an epicarp, with or without a fleshy mesocarp and with a paleaceous, crustaceous, ligneous or osseous endocarp, 1–3-or more locular
Pistillode often present, variously shaped
Stamens (1–)3–100(–1000), the filaments free or connate into a central column, simple or rarely branched, anthers 2(–4)-thecous, dehiscing longitudinally, rarely by pores, erect or inflexed in bud, with the thecae usually parallel and adnate to the connective throughout, sometimes free at the base, occasionally completely free and erect, divaricate or pendulous, rarely with the thecae superposed or laterally fused to form an annulus
Staminodes occasionally present, usually subulate, or 0
Ovary superior, sessile or rarely stipitate, 1–4(–20)-locular but most commonly 3-locular; placentation axile, with the ovules solitary or 2 and collateral in each locule and pendulous from its inner angle, anatropous, hemitropous or amphitropous, epitropous, crassinucellate, with a ventral raphe and with the hilar region between the raphe and the epimicropylar obturator, when the latter present; funicle often thickened; styles 1–4(–20), usually 3, free or united, erect or spreading, entire, bifid, multifid or laciniate, with the inner face usually stigmatic throughout and smooth, granulate, papillose or fimbriate and often tinged reddish or purplish
Stipules free or connate, sometimes spathaceous, membranaceous, capilliform, glandular or spiny, subpersistent, readily caducous or absent
Leaves usually alternate, sometimes opposite, rarely whorled, occasionally all three, green or scarious and squamiform, petiolate or sessile, stipulate or exstipulate, simple, lobed or compound, entire or variously toothed, peltate or not, palminerved or penninerved, often with a pair or several pairs of basal glands at or near the petiole insertion, and/or sometimes minutely pellucid-glandular-punctate beneath
Inflorescences terminal, or axillary, lateral or leaf-opposed, cymose or paniculate, or racemose or spicate, or with the flowers aggregated into glanduliferous involucrate pseudanthia (cyathia), which may themselves be aggregated into pseudopleiochasial hyperinflorescences, or into involucrate capitula, or else with the flowers fasciculate or solitary, ramiflorous or cauliflorous
Prostrate, erect or scandent, annual biennial or perennial, dioecious or monoecious herbs, shrubs or trees, succulent or not, spiny or unarmed, sometimes poisonous, sometimes with phylloclades, with or without a milky latex or coloured sap
Indumentum absent or of simple, branched or stellate hairs or peltate scales, the hairs sometimes urticating
Seeds 1–2 per locule, or by abortion 1 per fruit, carunculate or not, often myrmecochorous; sarcotesta sometimes present; sclerotesta thin, crustaceous to thick, osseous; endosperm copious, fleshy, or absent; embryo straight to curved or folded, extending for most of the length of the seed; radicle superior; cotyledons usually broader than the radicle, flat, rarely thick and fleshy or folded
Fruit smooth, wrinkled, warty, tubercled, horned or winged, rarely inflated, often schizocarpic, dehiscing septifragally and septicidally into 1–4(20) (but usually 3) bivalved cocci leaving a persistent angled or winged columella, the valves then dehiscing loculicidally, or else fruit loculicidally dehiscent into 3 separate valves, or breaking up irregularly, or else indehiscent, drupaceous or subdrupaceous, with a thin epicarp, with or without a fleshy mesocarp and with a 1–3(more)-locular paleaceous, crustaceous, ligneous or osseous endocarp
Ovary superior, sessile or rarely stipitate, 1–4(20)-locular but most commonly 3-locular; placentation axile, with the ovules solitary or paired and collateral in each locule and pendulous from its inner angle, anatropous or hemitropous, rarely orthotropous (Panda), crassinucellate, bi-integumental, hilum between the ventral raphe and the epimicropylar obturator, when present; funicle often thickened; styles (1)3(4)(20), free or connate, erect or spreading, entire, bifid, multifid or laciniate, the inner surface usually stigmatic throughout, smooth, granulate, papillose or fimbriate, often reddish- or purplish-tinged
Staminodes absent or occasionally present, usually subulate
Stamens (1)3–100(1000), the filaments free or variously connate, simple or rarely branched, anthers erect or inflexed in bud, 2–4-thecous with the thecae usually parallel and adnate to the connective throughout, sometimes free at the base, occasionally completely free and erect, divaricate, horizontal or pendulous, rarely with the thecae superposed or laterally fused to form an annulus, dehiscing by slits longitudinally, obliquely or laterally, less often by pores (not Africa)
Pistillode (non-functional ovary) often present, variously shaped
Corolla in one or both sexes of 3–6 free or rarely united subvalvate or imbricate petals, or petals minute or absent
Disk in the male flowers of 5–6 (occasionally more) free extrastaminal and/or interstaminal glands, less often the disk annular or cupular and extrastaminal or lobed, lobulate and intrastaminal with the stamens enfolded by the lobes, or else the disk receptacular, domed and aperturate with the stamens arising through the apertures, or disk absent; in the female flowers hypogynous, annular, flat or cupular, entire or lobed, rarely of separate glands, usually persistent, or absent
Flowers unisexual, usually actinomorphic, small to minute
SELECTED REFERENCES Punt, W. 1962. Pollen morphology of the Euphorbiaceae with special reference to taxonomy. Wentia 7: 1–116. Radcliffe-Smith, A. 2001. Genera Euphorbiacearum. Kew. Tokuoka, T. 2007. Molecular phylogenetic analysis of Euphorbiaceae sensu stricto based on plastid and nuclear DNA sequences and ovule and seed character evolution. J. Pl. Res. 120: 511–522. Webster, G. L. 1967. The genera of Euphorbiaceae in the southeastern United States. J. Arnold Arbor. 48: 303–361, 363–430. Webster, G. L. 1994. Synopsis of the genera and suprageneric taxa of Euphorbiaceae. Ann. Missouri Bot. Gard. 81: 33–144. Webster, G. L. 1994b. Classification of the Euphorbiaceae. Ann. Missouri Bot. Gard. 81: 3–32. Webster, G. L. 2014. Euphorbiaceae. In: K. Kubitzki et al., eds. 1990+. The Families and Genera of Vascular Plants. 10+ vols. Berlin etc. Vol. 11, pp. 51–216. Wurdack, K., P. Hoffmann, and M. W. Chase. 2005. Molecular phylogenetic analysis of uniovulate Euphorbiaceae (Euphorbiaceae sensu stricto) using plastid rbcL and trnL-F DNA sequences. Amer. J. Bot. 92: 1397–1420.
Lynn J. Gillespie "Euphorbiaceae A. L. Jussieu in Flora of North America @ efloras.org" eFlora. Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA., 2017. Web. Accessed February 2018.