Woody vines. Petiole eglandular or bearing 2–8 small glands in 2 rows; lamina usually bearing few to many small glands impressed in abaxial surface in 1–3 rows between midrib and margin; stipules minute, triangular, borne on proximal half of petiole or at junction of petiole and stem, or apparently lacking. Inflorescence a terminal or lateral compound dichasium or paniculate dichasium, strictly decussate, with the flowers borne in pairs or umbels or corymbs of 4 (–8); floriferous peduncle well developed; bracteoles eglandular, broad and rounded (elliptical or obovate), borne between middle and apex of peduncle. Sepals valvate, completely concealing petals during enlargement of bud, revolute in anthesis, all 5 biglandular; corolla bilaterally symmetrical, the posterior petal somewhat different from lateral 4; petals yellow turning red in age, glabrous; androecium radially symmetrical; stamens filaments ca. 1/2-connate, straight, those opposite sepals slightly longer than those opposite petals; anthers alike, glabrous; gynoecium radially symmetrical; ovary with the carpels completely connate; styles ± straight, subequal, stout, truncate at apex with the stigma terminal or nearly so. Samaras separating from a prominent pyramidal torus; samara suborbicular or transversely elliptical (in M. bracteosa the mericarps with the wings reduced to coriaceous or corky outgrowths), the lateral wings membranous with many looping anastomoses, cleft to nut at apex, continuous at base, the margin entire, undulate, or coarsely toothed; dorsal wing free from lateral wing at base, extended forward at apex through gap in lateral wing; intermediate winglets none or 1–several seta-like structures as high as width of dorsal wing or smaller; ventral areole broadly ovate. Chromosome number unknown.
Four species of northern South America, growing in roadside thickets and secondary vegetation, along rivers, and in forests. [map]
Malpighiodes is distinguished by the dichasial inflorescence with the flowers strictly decussate and borne in pairs or umbels or corymbs of 4 (–8), the broad rounded bracteoles, the valvate sepals completely concealing the petals until anthesis, all five biglandular, and the petals glabrous, yellow turning red in age. The mericarps in M. guianensis and M. leucanthele are samaras with a membranous lateral wing, while those of M. bracteosa have the wings reduced to coriaceous or corky outgrowths; this kind of reduction in samaras (presumably as an adaptation for dispersal by water) has evolved in many genera of Malpighiaceae. For additional examples of such reduced fruits, see Callaeum antifebrile (photo and drawing), Heteropterys complicata (drawing), Hiraea quapara (photo and drawing), Jubelina magnifica (photo and drawing), J. riparia (photos), and Lophopterys splendens (drawing).
Reference: W. R. Anderson (2006b, pp. 191, 193–199), partial revision: description of genus, key to species, nomenclature of species, but no descriptions of species (Malpighiodes only: pdf; entire paper: pdf); unpublished notes on species of Malpighiodes.
Photos: M. guianensis, M. leucanthele
Drawings: M. bracteosa, M. guianensis