Peperomia is one of the largest genera of basal angiosperms, with about 1,600 species, distributed pantropically. The Brazilian oceanic island of Trindade is located about 1,200km off the Brazilian coast; its maximum altitude is 620ma.s.l. and its area is 9.28km2. Among the 113 species of vascular plants reported for Trindade Island there are two species of Peperomia: Peperomia beckeri, an endemic species known only from the type specimen; and Peperomia glabella.We re-evaluated specimens attributed to P. glabella from Trindade Island and compared them to specimens from the continent. The comparison included morphological analyses of the vegetative and reproductive organs, and a molecular phylogenetic study using the molecular markers trnK/matK and ITS. The trnK/matK marker showed significant differences between Peperomia from the mainland and Trindade. Together, these studies showed that the Peperomia occurring on Trindade is a species that differs both from those previously recorded on Trindade Island and from those on the continent, leading us to describe a new species. Peperomia segregata is endemic to Trindade, and would likely be considered critically endangered according to the IUCN criteria.

Figure S1Principal component analysis (PCA) of specimens of Peperomia segregata and Peperomia glabella and varietities. The red dots are the specimens of Peperomia segregata and the black dots are the specimens of Peperomia glabella. The blue dots are the specimens identified as Peperomia glabela var. glabella, the pink dots are the specimens identified as Peperomia glabella var. nervulosa, the green dots are the specimens identified as Peperomia glabella var. nudipetiolata and the purple dots are the specimens identified as Peperomia glabella var. nigropunctata.Supplementary Figure 1.tif