A taxonomic revision of Tragia (Euphorbiaceae) in Gabon, with a description of two threatened new species

Background and aims – The production of the Flora of Gabon is advancing biodiversity discovery and highlighting knowledge gaps in complex genera, such as Tragia. By studying this genus, we have identified new species to science and documented new country records for Gabon. Material and methods – Standard practices of herbarium taxonomy were applied to study material from institutions with important holdings from Central Africa.

Key results – After a critical study of specimens from Gabon and surrounding territories, a total of six species of Tragia were identified in the country. Two new species, Tragia flagellata and T. sericea, are described and preliminarily assessed as Endangered (EN) and Vulnerable (VU), respectively. We cite Tragia mildbraediana and T. zenkeri as new records for Gabon.

Comprehensive nomenclatural information is supplied and three lectotypes are designated. An updated identification key, an original illustration, photos of the new species, and maps are provided.