Jatropha mcvaughii Dehgan & G.L.Webster

  • Authority

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

  • Family

    Euphorbiaceae

  • Scientific Name

    Jatropha mcvaughii Dehgan & G.L.Webster

  • Type

    Type. Mexico. Jalisco: Playa Scandida, Dec 1974, B. Dehgan B74.206 (holotype: DAV; isotype: NY). [Specimens from wild-collected, dormant seedlings grown at the University of California, Davis greenhouses, harvested 17 Oct 1979].

  • Synonyms

    Jatropha curcas var. rufus McVaugh

  • Description

    Species Description - Shrubs or small trees, 1.5-3.5 m tall, dioecious. Stems: gray, erect, smooth, leaf scars crescent-shaped, younger branches pubescent, trunk fissured or cracked but not peeling; latex clear to cloudy in older stems. Leaves: deciduous; stipules caducous but narrowly lanceolate when present; petioles 8-12 cm long and 1.5-2.5 mm in diam.; blades ovate-cordate in outline, mostly 15-29.5 cm long and nearly as wide, with 5-7 (-9) lobes, 62-6.1 cm wide, the 3-4 upper lobes deeper than lower, membranous, base broadly cordate, margins entire and devoid of glands, apex cuspidate, venation palmate, with 7(-9) primary veins; pubescent on both surfaces particularly on the veins. Inflorescences: terminal, compound cymes in both sexes but pistillate few-flowered; peduncles 7-2 cm long in staminate and 5.5-6.5 cm in pistillate, tomentose in both, paracladia terminating in a single flower, bracts entire, lanceolate, pubescent, 3-6.5 mm in staminate; pedicels of staminate flowers 1-1.5 cm, somewhat longer in the pistillate, tomentose. Staminate flowers: sepals lanceolate to ovate-elliptic, 4-7 x 2-3 mm, partially imbricate, acuminate, margins entire (not glandular); corollas tubular-campanulate, bright green, petals obovate, 5.5-8 x 2-3.5 mm, connate to about ½ or more of length, villous abaxially, hirsute adaxially; disc segments 5, massive, ellipsoid, ca. 2-3.5 x 1-1.5 mm; stamens 10, monadelphous-uniseriate at anthesis, filaments ca. 3-5 mm long, connate to ca. ½ of length; anthers oblong elliptic, somewhat flattened at apex, about 1.5-2 mm long. Pistillate flowers: like staminate but sepals 7-10 x 3.5-5 mm, imbricate; petals 1-1.3 x 2.5-4 mm; carpels 3, glabrous; styles thickened, connate to ca. ½-¾ of length, stigmas massive, dark green. Capsules: 3-locular, ellipsoid, ca. 20 x 15 mm, ± fleshy, tardily dehiscent. Seeds: light brown, ellipsoid, 10-12 x 8-10 mm, caruncle appressed to the beak and nearly vestigial, ca. 1 x 1.5-2 mm.

  • Discussion

    Local name and uses. Sangregado. Although Jatropha Mcvaughii is much less productive in fruit and seed than J. curcas, probably because of its dioecious nature, the species has been cultivated in recent years for its seed oil similar to J. curcas. Also, it is likely that because of its vegetative similarity to J. curcas, plants may be used for fence posts and medicinal purposes.

    The species originally was described by McVaugh (1945b) as Jatropha curcas var. rufus, solely on the basis of its pubescence. However, it differs from J. curcas in its shrubby growth habit; fissured bark; much larger leaves with deeper lobes and pubescence; dioecious gender; elongated male and few-flowered, female inflorescences; darker green (as opposed to yellowish green), more pubescent petals; longer corolla tubes; thick style column with undilated stigmas; and smaller brownish (as opposed to black) seeds. Some specimens appear to be hybrids with J. curcas. Annotation of the isotype at NY by Fernández Casas in 1981 as J. curcas is not warranted.

  • Distribution

    From Mazatlán in State of Sinaloa, south to Nayarit and Jalisco, at ca. 350 m, in rocky, deciduous woodlands and in arid valleys of Sierra de Manantlan. Flowering and fruiting in mid-spring and early summer.

    Jalisco Mexico North America| Nayarit Mexico North America| Sinaloa Mexico North America|