%0 Journal Article %T Two new species in the Matelea stenopetala complex (Apocynaceae, Asclepiadoideae) from the Guiana Shield and Amazonian Brazil %A Alexander Krings %A Gilberto Morillo %J PhytoKeys %D 2012 %I Pensoft Publishers %R 10.3897/phytokeys.17.3485 %X Two new species in the Matelea stenopetala complex (Apocynaceae, Asclepiadoideae) are described from the Guiana Shield and Amazonian Brazil: Matelea brevistipitata Krings & Morillo, sp. nov. and M. trichopedicellata Krings & Morillo, sp. nov. The new species belong to a small group of adaxially-pubescent-flowered taxa within the complex, including M. hildegardiana and M. pakaraimensis. The new species are described and a dichotomous key is provided. %K Gonolobinae %K Matelea %K Neotropics %K twining vines %K taxonomy %U http://www.pensoft.net/journals/phytokeys/article/3485/