Taxonomy, distribution and new taxa from the Habenaria crucifera (section Nudae , Orchidaceae) aggregate from Brazil and the Guianas

The taxonomy, morphology, and geographic distributions of Habenaria crucifera and related species in section Nudae were investigated. Habenaria galeandriformis and H montiswilhelminae are included in the affinity of H. crucifera and four new taxa are described: H. cardiostigmatica, H. crucifera var. brevidactyla, H. guaraensis, and H. spanophytica. These species form a subgroup within section Nudae, characterized by linear grass-like leaves that are appressed to the stem; green flowers; simple or discretely bipartite petals; a tripartite lip; a rostellum midlobe completely placed between the two anther loci; stigma lobes that are closely parallel; and a separated hemipollinarium. This group of species ranges from the Guianas to the state of Rio Grande do Sul in southern Brazil, but is concentrated in the cerrado of central Brazil. Diagnostic characters, illustrations, descriptions and notes on the habitat, distribution, phenology, and conservation status are presented for all species here recognized. A taxonomía, morfologia e distribuiçao geográfica de Habenaria crucifera e especies relacionada na secäo Nudae foi investigada. Habenaria galeandriformis e H.montiswilhelminae sao incluidas na afinidade de H. crucifera e quatro taxons novos sao descritos: H. cardiostigmatica, H. crucifera var. brevidactyla, H. guaraensis e H. spanophytica. Essas especies formam um subgrupo da secäo Nudae caracterizado pelas folhas graminóides, lineares, apressas ao caule, flores verdes, pétala simples ou discretamente bipartida, labelo tripartido, lobo mediano do róstelo completamente compreendido entre os lóculos da antera, lobos do estigma próximos, paralelos, e hemipolinários separados. A distribuiçao das especies estende-se das Guianas até o estado do Rio Grande do Sul no sul do Brasil, mas concentra-se no cerrado do Brasil central. Caracteres diagnósticos, ilustracöes, descricäo e comentarios sobre o habitat, distribuiçao, fenologia e status de conservaçao säo apresentados para cada especie.