Stigmaphyllon brachiatum Triana & Planch.

  • Authority

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

  • Family

    Malpighiaceae

  • Scientific Name

    Stigmaphyllon brachiatum Triana & Planch.

  • Description

    Deprecated: mb_convert_encoding(): Handling HTML entities via mbstring is deprecated; use htmlspecialchars, htmlentities, or mb_encode_numericentity/mb_decode_numericentity instead in /home/emu/nybgweb/www-dev/htdocs/science-dev/wp-content/themes/nybgscience/lib/VHMonographsDetails.php on line 179

    Species Description - This species seems hardly different from Stigmaphyllon hypoleucum except for the stylar character given in the key; the appendages of the posterior styles also tend to be smaller in S. brachiatum. See the description of S. hypoleucum.

  • Discussion

    Type. Triana, Villavicencio, Colombia. The shape of the stylar appendages is traditionally important in the taxonomy of Stigmaphyllon, and on that basis Niedenzu placed S. brachiatum and S. hypoleucum in different subgenera. However, except for the presence or absence of lobes on the appendage of the anterior style the two species are indistinguishable. It seems probable that S. brachiatum is derived from S. hypoleucum by loss ofthe folioles on the anterior style. This idea is supported by Williams 11239, which is from the Medio Caura where S. hypoleucum is common and S. brachiatum unknown. Its anterior style is intermediate between the two forms, and in the circumstances the intermediate form seems likelier to have originated directly through modification of local S. hypoleucum than through hybridization. Indeed, Stigmaphyllon brachiatum may not be a monophyletic taxon. In Bolivar it mimics eastern forms of S. hypoleucum, while the populations of western Amazonas and Colombia are more like the Orinoco populations of S. hypoleucum, which suggests its origin on at least two occasions, perhaps more. This raises an obvious question about its taxonomic status, which I shall not attempt to resolve here. A most interesting collection is Maguire et al 44142 from the Rio Caqueta in Colombia. The anterior style has an extended axis and small, triangular folioles, the result being unlike the usual condition in either species. In other respects the plants are most like Colombian collections of S. brachiatum. Stigmaphyllon hypoleucum sensu stricto is not yet known from Colombia, but Maguire's intermediate leads m e to predict that it will be found there, probably on the lower Rios Vaupes, Apaporis, or Caqueta.

  • Distribution

    Distribution. Northern South America. Guayana collections: VENEZUELA. Bolívar: Carretera El Pao-San Felix, elev 250 m, Aristeguieta 2285 (NY, VEN); Santa Maria de Erebato, 5°5'N, 64°40'W, elev 350 m, Steyermark et al 109847 (NY). Amazonas: San Juan de Manapiare, elev 375-425 m, Agostini 1504 (MICH); Mavaca, Aristeguieta & Lizot 7371 (NY, VEN); Isla del Raton, elev 90 m, Breteler 4721 (VEN, WAG); El Maco, Rio Ventuari, Foldats 108A (VEN); Boca del Vichada, elev 100 m. Holt & Gehriger 221 (NY,

    Venezuela South America| Colombia South America| Guyana South America| Suriname South America| French Guiana South America| Brazil South America| Ecuador South America|