RESUMEN
109 species of Ipomoea L. are recorded from Bolivia. This total includes six new country records and two species, I. prolifera J. R. I. Wood & Scotland and I. inaccessa J. R. I. Wood & Scotland, which are described as new, while I. jujuyensis O'Donell is excluded having been included previously in error. The little-known I. subalata Hassl. is described in full and compared with I. chondrosepala Hallier f. and other species with which it has been confused. The paper is illustrated with line drawings, photographs and distribution maps of the main species discussed.
RESUMEN
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.
RESUMEN
BACKGROUND: At a global scale, the temperate zone is highly fragmented both between and within hemispheres. This paper aims to investigate how the world's disjunct temperate zones have been colonised by the pan-temperate plant group Convolvuleae, sampling 148 of the c. 225 known species. We specifically determine the number and timing of amphitropical and transoceanic disjunctions, investigate the extent to which disjunctions in Convolvuleae are spatio-temporally congruent with those in other temperate plant groups and determine the impact of long-distance dispersal events on diversification rates. RESULTS: Eight major disjunctions are observed in Convolvuleae: two Northern Hemisphere, two Southern Hemisphere and four amphitropical. Diversity in the Southern Hemisphere is largely the result of a single colonisation of Africa 3.1-6.4 Ma, and subsequent dispersals from Africa to both Australasia and South America. Speciation rates within this monophyletic, largely Southern Hemisphere group (1.38 species Myr(-1)) are found to be over twice those of the tribe as a whole (0.64 species Myr(-1)). Increased speciation rates are also observed in Calystegia (1.65 species Myr(-1)). CONCLUSIONS: The Convolvuleae has colonised every continent of the world with a temperate biome in c. 18 Myr and eight major range disjunctions underlie this broad distribution. In keeping with other temperate lineages exhibiting disjunct distributions, long-distance dispersal is inferred as the main process explaining the patterns observed although for one American-Eurasian disjunction we cannot exclude vicariance. The colonisation of the temperate zones of the three southern continents within the last c. 4 Myr is likely to have stimulated high rates of diversification recovered in this group, with lineage accumulation rates comparable to those reported for adaptive radiations.