In the context of recent molecular phylogenies of the basal grades of Compositae, we investigated the utility of pollen morphology within the tribe Gochnatieae. The pollen of 64 species of Anastraphia, Cnicothamnus, Cyclolepis, Gochnatia, Pentaphorus, and Richterago was studied using light microscopy and scanning electron microscopy. In addition, three extra-Gochnatieae genera (Ianthopappus, Leucomeris, and Nouelia) were examined as they were traditionally morphologically related to members of the tribe Gochnatieae. Three of the species of Gochnatieae were examined using transmission electron microscopy. Two pollen types, and two new subtypes, have been recognized on the basis of the pollen shape, size, and exine sculpture. The pollen features of Gochnatia sect. Moquiniastrum and G. cordata are similar and distinctive within the genus and support the recently re-circumscribed section Hedraiophyllum. Within the species with echinate pollen surface, the distinctive spine length of Anastraphia supports its recent resurrection as a genus. The identity of Pentaphorus could not be supported by pollen features as was for other morphological characteristics. The pollen features shared across Cyclolepis, Ianthopappus, Leucomeris, Nouelia and Gochnatia sect. Moquiniastrum, as well as those shared by Richterago and Anastraphia could be a result of parallel evolution.

The Caribbean Islands are one of the ten insular biodiversity hotspots that are defined based on endemicity, massive habitat loss and vulnerability to extinction. Asteraceae genera endemic to islands have provided well known examples of plant radiation worldwide and illustrate the importance of these insular systems for evolutionary and conservation studies. A review of known patterns of taxonomic diversity and molecular cladistics is provided for Asteraceae genera and species endemic in the Caribbean Island biodiversity hotspot. We found that when compared with other island systems worldwide the Caribbean Islands have the highest number of endemic genera (41), have endemic genera in the highest number of tribes, and harbor the only Asteraceae tribe endemic to an island system, the Feddeeae which is restricted to Cuba. These unique patterns identify the Caribbean Islands as the most important insular area of endemism for this major plant family. Molecular cladistic studies are limited to only seven species in seven endemic genera and six endemic species in five non-endemic genera. These few studies are however relevant as: (1) they confirm the tribal status of the Feddeeae, (2) suggest colonization events from the highlands of Cuba toward low elevation and geologically recent areas of the Bahamas and South Florida, (3) provide evidence for biogeographical links to remote regions of the Pacific Basin, and (4) identify sister relationships with continental taxa, mostly from North America.Resumen Las Islas del Caribe son uno de los diez "punto calientes" insulares de biodiversidad, los cuales vienen definidos por sus niveles de endemicidad, masiva pérdida de habitat y vulnerabilidad y extinción. Asteráceas endémicas de islas han proporcionado ejemplos muy bien conocidos de radiación vegetal a nivel mundial, éstos ilustran la importancia de los sistemas insulares en estudios evolutivos y de conservación. Se presenta una revisión de las pautas de diversidad taxonómica y de