Manihot xavantinensis D.J.Rogers & Appan

  • Authority

    Rogers, David J. & Appan, S. G. 1973. Manibot, Manihotoides (Euphorbiaceae). Fl. Neotrop. Monogr. 13: 1-272. 1 chart. (Published by NYBG Press)

  • Family

    Euphorbiaceae

  • Scientific Name

    Manihot xavantinensis D.J.Rogers & Appan

  • Type

    TYPE. Harley, Souza & Fereira 10381: Brasil, Mato Grosso: Route 3, ca 2 km SE of expedition (Royal Society /Royal Geographical Society expedition 1967-1969) base camp at 12° 49* S, 51° 46* W, 1 Oct 1968 (holotype, K; isotype, NY).

  • Description

    Latin Diagnosis - Frutices gracili, ad 1.0 m altus. Folia trilobus; lobi median ellipticis, ca 7.0 cm longa, ca 3.0 cm lata; basis loborum constrictus, 0.4 cm latae. Inflorescentia fasciculus subspicatorum racemi, ca 8.0 cm longa, omnies partes glabra; bracteolae et ramuli setiformis. Fructi parvi, 1.1 cm longae. Semina prominens caruncula.

    Description - Slender shrubs, to 1.0 m tall, latex white. Young stems glabrous, brown with purplish tinge; mature stems glabrous, dark brown with purplish tinge. Leaves alternate; stipules caducous; petioles less than 5.0 cm long, glabrous, terete, purplish, petiole attachment to lamina basal, nonpeltate; lamina coriaceous, abaxial surface dark green, abaxial surface glaucous, abaxial surface wax pattern reticulate with discrete rings at magnifications of × 40; venation camptodromous, veins glabrous, midribs slender, less than 0.1 cm in diameter; lamina palmately 3 lobed; median lobes elliptic, ca 7.0 cm long, ca 3.0 cm wide, apex acute, base acute, base of lobes constricted, 0.4 cm wide, width between base of sinus and petiole-midrib junction less than 0.3 cm, lobes slightly overlapping at sinus; lowest lobes more or less same, as median lobes in outline and size, slightly nonsymmetric. Inflorescence monoecious, terminal, a cluster of subspicate racemes arising from one basal point, ca 8.0 cm long; all parts glabrous; bracteoles and bractlets setaceous, less than 0.3 cm long, less than 0.1 cm wide. Pistillate flowers restricted to the base of the upper 1/3 of the inflorescence, pedicels 1.5 cm long, tepal 0.8 cm long, yellowish green internally, purplish tinged externally, cleft to base into 5 strap-shaped lobes, ovary elongated. Staminate buds ovoid-ellipsoid, flowers small, tepal 0.7 cm long, yellowish green internally, purplish tinged externally, cleft 1/3 way down into 5 lobes, stamens 10, in 2 whorles of 5 each, superior whorl 0.6 cm long, inferior whorl 0.5 cm long, anthers deep yellow. Capsules small, 1.1 cm long; surface smooth, without wings; apex rounded; dehiscence septicidal. Seeds small 0.8 cm long, 0.5 cm wide, oblong; caruncle very prominent, nearly 1/3 as long as the seeds. Fig 5 2D and 5 3 A.

  • Discussion

    This distinct new species was represented by very adequate herbarium collections. Its closest relative is Manihot sparsifolia from which it is distinguished by the constricted leaf lobe bases, slender midribs and shorter petioles.

  • Common Names

    mandioca, Mandioca braba

  • Distribution

    (Fig 52C).

    Brazil South America| Mato Grosso Brazil South America|