Diplopterys

• Authority

  Maguire, Bassett. 1978. The botany of the Guayana Highland--part XI. Mem. New York Bot. Gard. 32: 1-391.

• Family

  Malpighiaceae

• Scientific Name

  Diplopterys

• Description

  Genus Description - Woody vines, often riverine. Leaves opposite, sericeous to glabrate with short, straight, appressed hairs, the stipules small, free, interpetiolar. Inflorescence axillary, shorter than the subtending leaves, of 1-several simple 4-flowered umbels or 1-several racemes of up to 7 4-flowered umbels; floriferous peduncle absent; bracts and bracteoles similar, lingulate, eglandular, spreading, persistent, borne in a cluster of 12 at base of umbel. Calyx with the lateral 4 sepals biglandular, the anterior eglandular or rarely 1-glandular. Petals yellow, fimbriate, abaxially sparsely sericeous. Stamens 10, all fertile, the filaments glabrous, those opposite the sepals longer than those opposite the petals, those ofthe 3 posterior stamens inflexed between the posterior styles, the anthers unequal. Ovary of 3 free carpels adnate to a common torus, 1 anterior and 2 posterior, all fertile, densely hairy; styles 3, free, with capitate terminal stigmas. Fruit schizocarpic, breaking apart into 3 mericarps (or fewer due to abortion) separating from a short pyramidal torus; nut of the mericarp with a hard woody pericarp, bearing a dorsal crest and 2-several lateral winglets or crests parallel to the areole and interconnected by ridges, sericeous.

• Discussion

  Type. Diplopterys pauciflora (G. F. W . Meyer) Niedenzu. Diplopterys was estabhshed by Jussieu for the single species D. paralias, which is now considered a synonym for D. pauciflora. Niedenzu amplified the genus to include Jubelina, Mezia, and Diplopterys spruceana Niedenzu, as well as D. pauciflora. His amplified Diplopterys is a very artificial group that must be dismembered. Jubelina and Mezia are recognized here as distinct mascagnioid genera. Diplopterys spruceana is here transferred to Mascagnia, as M. heterocarpa, because of its similarity to M. leucanthele and M. guianensis. That reduces Diplopterys to its type again, to which one can add the species treated here and two new ones soon to be described by Dr. Bronwen Gates. These constitute a group of closely related species clearly derived from Banisteriopsis, indeed, scarcely distinguishable from it in flower. The samara has lost the elongated dorsal wing of Banisteriopsis, the nut is enlarged, and the lateral winglets are enlarged and interconnected, so that the two genera are quite easily distinguished in fruit. Dr. Gates has decided to maintain Diplopterys as a natural and convenient segregate from Banisteriopsis, a decision which I support. She will include a brief revision of Diplopterys in her forthcoming monograph of Banisteriopsis, which see for more discussion of the relationship of the two groups. The treatment of Diplopterys in this paper is adapted from her manuscript.