Monographs Details: Jatropha isabelliae Müll.Arg.
Description:Species Description - Subshrubs, to 50 cm. Stems: herbaceous, succulent, green but tinged reddish early, shoots few, erect or decumbent, arising from a long, woody, subterranean, rhizomatous caudex; latex clear and viscous. Leaves: deciduous together with cauline shoots, stipules branched, stipitate glands, 4-7 mm long; petioles sessile to subsessile, 0-0.2 mm; blades heteromorphic, widely elliptic, infrequently 2- or 3-lobed, 3-7.2 x 6.5- 10.5 cm, membranous early but coriaceous when fully developed, base acute to rounded, margins glandular, apex acute, venation pinnate (palmate when lobed), pubescent on both surfaces. Inflorescences: terminal, few-flowered cymes, peduncles 2.5-6.5 x 1-4 cm; bracts lanceolate, 5-11 mm long, margins glandular, pubescent on both surfaces; pedicels 2-3 mm. Staminate flowers: sepals lanceolate, 4.5-6 x 1-1.6 mm, distinct, margins glandular, apex acuminate, glabrous on adaxial surface but sparsely pubescent on adaxial; corollas campanulate, red-maroon or yellow-green, petals ob-ovate, 6.5-9 x 2.8-3.8 mm, apex rounded, reflexed, pubescent on adaxial surface but glabrous or very sparsely pubescent on abaxial; stamens 8(-9), diadelphous-biseriate (5 + 3), filaments of outer series 3-5 mm long, those of inner series 3.5-6 mm, both connate to ca. ¾ of length. Pistillate flowers: like staminate but sepals 4.6-6.8 x 1.1-1.7 mm, distinct or basally connate to ca. ¼ of length; corollas rotate-campanulate, petals 6.8-11 x 2.8-4.1 mm, connate at base; carpels 3, styles 2-3 mm, distinct. Capsules: ellipsoid, 1.2-1.3 x 0.9-1.1 cm, glabrous, 3-locular but distinctly 6-lobed, explosively dehiscent. Seeds: golden brown, ellipsoid 1 x 0.7 cm, caruncle large and prominent.
Distribution and Ecology: Southern and southwestern Brazil and Paraguay, relatively widespread usually on red clay soil and sometimes in rocky areas. Flowering and fruiting in mid-spring and summer.