Solenopsis gutermannii (Campanulaceae), a New Species from Kefalonia (Ionian Islands, Greece)

A new species of Solenopsis (Campanulaceae), S. gutermannii is described and illustrated. It is endemic to Kefalonia island, Greece, where it is very rare and localized in flat clay surfaces that are periodically submerged. This species is a very small annual hygrophyte, characterized by rosulate leaves or with slightly caulescent stems, long-pedunculated flowers, bilabiate corolla, and papillate near the throat. It exhibits close affinities primarily with S. minuta, with which it was previously identified, and additionally with S. antiphonitis, due to similarities in habit and certain flower traits. Nevertheless, several relevant morphological features serve to distinguish it from these species. Its morphology, seed coat and pollen SEM micro-sculpturing, ecology, phenology, distribution, conservation status, and taxonomic relationships are also examined.