The rare aquatic angiosperm Elatine gussonei (Elatinaceae) is more widely distributed than previously thought

Elatine gussonei (Sommier) Brullo et al. is a rare freshwater plant previously assumed to be endemic to Lampedusa and the Maltase archipelago. Taxonomic uncertainties within the Elatine genus may have caused E. gussonei populations to be overlooked in the Mediterranean region. To clarify the distribution of E. gussonei, we reviewed Elatine specimens from 12 herbaria and conducted eight field surveys in Mediterranean countries. Through our herbarium review we documented previously unknown occurrences of E. gussonei from Portugal, Spain, France, Algeria, Egypt, Cyprus and Israel. Additionally, in field studies we found populations from Cyprus, Morocco and Spain. Elatine gussonei is therefore more widespread than previously assumed, although the species still has a scattered distribution around the Mediterranean and many of the records are old. We found intact E. gussonei seeds in the faeces of migratory Greylag Geese (Anser anser) collected in southern Spain, suggesting that E. gussonei has a high capacity for long distance dispersal.