New records of green algae (Chlorophyta) for the Caribbean coast of Costa Rica

The Caribbean coast of Costa Rica is an area of significant floristic diversity. Five new records of the occurrence of marine green algae (Chlorophyta) are reported for this region, namely, Ulva rotundata, Derbesia vaucheriformis, Avrainvillea asarifolia, Halimeda pumila and Penicillus capitatus f. laxus. Each taxon is described, and their principal diagnostic characters are contrasted with those of other members of the genus present in the area of study. With the exception of the Avrainvillea asarifolia, all the species reported here are new occurrences for the Central American region.