Jatropha

  • Authority

    Dehgan, Bijan. 2012. . Fl. Neotrop. Monogr. 110: 1--274. (Published by NYBG Press)

  • Family

    Euphorbiaceae

  • Scientific Name

    Jatropha L.

  • Synonyms

    Curcas, Mozinna, Loureira, Zimapania, Collenucia

  • Description

    Genus Description - Trees: shrubs; rhizomatous subshrubs; or tuberous-caudiciform, perennial herbs; monoecious, dioecious, or rarely gynodioecious. Latex universally produced, pale and watery, cloudy, yellow to distinctly red, but never milky white, powdery when dry; laticifers articulated, nonarticulated, or idioblastic. Chambered, crystalliferous parenchyma present or absent. Cyanogenic glucoside compounds absent (present in other Crotonoideae). Roots: 5, 1 deep central and 4 shallow outer that often become fleshy with parenchymatous storage tissue. Stems: terete; green, gray, red, or reddish brown; sparsely to densely branched, smooth or often with distinct lenticels or lines; bark of arborescent species smooth, wrinkled, with fissures and cracks, or often peeling in thin yellow or gray sheets, with or without pubescence, sometimes with protruding, spinose, petiolar scars; short shoots present in xeric taxa. Leaves: alternate, long-petiolate to subsessile or rarely sessile; stipules simple or branched, sometimes stiff-glandular, long filiform, filiform and gland-tipped, reduced or caducous or obsolete, but never truly spinose in neotropical species; blades simple and unlobed to palmately 3- to 7-lobed or divided with 5-11 segments; venation mostly palmate or sometimes pinnate, brochidodromous or only exceptionally craspedodromous; margins entire, glandular, serrate, aculeate, or sometimes ciliate, with or without mucronate tips or glands; surfaces glabrous, glaucous, or with varying degrees of unicellular or multicellular-uniseriate, smooth or verrucate pubescence. Inflorescences: terminal, subterminal, lateral, or reduced to a few or solitary flowers in leaf axils; simple or compound, dichasial cymes, paracladia few to many with female flowers in proximal dichotomies in monoecious species and generally fewer than the males; coflorescences present and distinct, present but not distinct, or absent. Staminate flowers: sepals 5, distinct, imbricate, or ± connate; margins entire, glandular, serrate, or divided; corollas greenish, white, yellow, yellow-brown, pink, red, or bicolor, actinomorphic, rotate, campanulate, urceolate, subglobose, or tubular with 5 imbricate, free or coherent, or variously connate petals, glabrous or with various degrees of pubescence; disc entire, dissected, or lobed, of nectariferous glands; stamens 6, 8, or 10, dehiscing longitudinally; filaments distinct, monadelphous or diadelphous, uniseriate or biseriate; pollen grains binucleate, spheroidal, inaparturate, and with well-defined triangular or circular (in cross section) exinous excrescences or clavae (knobs), supported by circular or hexagonally formed murid ridges. Pistillate flowers: mostly similar to the staminate but sepals more often glandular-margined or distinctly foliaceous; petals as in the staminate but often somewhat larger; disk glands as in the staminate but larger; ovary mostly of 3 carpels but in some taxa reduced to 2 or 1, smooth, glabrous or pubescent; ovules 1 per locule; styles 3 or sometimes 2 or 1 (corresponding with locules of the fruits), distinct or variously connate, stigmas bifid, lobes massive or narrow and long-fimbriate. Fruits; 3-, 2-, or 1- locular capsules, often distinctly lobed, ± fleshy, explosively or tardily, septicidally or loculicidally dehiscent when dry, separating into individual cocci. Seeds: ellipsoid or spherical, solid gray-brown, black, or yellow or variously mottled with brown or black spots or lines; caruncle large and distinct or sometimes reduced or vestigial; testa crutaceous, endosperm present and copious; embryo spathulate; cotyledons generally broad and palmately 3- to 5-nerved, radicle short, germination phanero-cotylar or exceptionally cryptocotylar. Chromosome number 2n = 22 or rarely 2n = 44.