Remarkable disjunctions in Ipomoea species (Convolvulaceae) from NE Brazil and Central America and their taxonomic implications

Abstract

Recent collections of Ipomoea from North East Brazil have revealed a number of unexpected disjunct distributions. The most remarkable is that of I. eremnobrocha D. F. Austin, previously thought to be endemic to Panama but now known from three states in NE Brazil. Revision of Panamanian material named I. eremnobrocha unexpectedly showed that two distinct species had been treated under this one name. Specimens from the Chagres National Park area in Panama are described as a new species under the name I. isthmica J. R. I. Wood & Buril while I. eremnobrocha is retained as the correct name for the plant from the Altos de Campana in Panama and NE Brazil. An amended description of this species is given and a table of differences between the related species is provided. Two recently described species from Bolivia, I. graniticola J. R. I. Wood & Scotland and I. chiquitensis J. R. I. Wood & Scotland are recorded from NE Brazil several thousand km from their type localities. Attention is drawn to the role of granite inselbergs as sites of species with a disjunct distribution. A possible relative of I. chiquitensis is described as a new species from NE Brazil under the name I. melancholica J. R. I. Wood & Buril. The new species are illustrated with line drawings and maps of the unusual distribution patterns are provided.