Euonymusaquifolium (Celastraceae): Rediscovered in flowering with respect to its taxonomy, nomenclature, and rarity

Abstract A small population of Euonymusaquifolium (Celastraceae) with flowering plants was discovered more than 100 kilometers away from its type locality. The incomplete original description of this species is supplemented here with floral materials since it is known from only two gatherings of fruiting specimens. Its 5-merous flowers and two ovules per locule support its position in Euonymus, and this inference is further reinforced by phylogenetic analysis based on the nuclear internal transcribed spacer (ITS) of rDNA. The specific epithet has long been treated as “aquifolius” to agree with the generic gender of Euonymus. But after examination of the protologues of this and other related species described simultaneously by the same authors, as well as their handwritten annotations attached on the type specimens, we conclude that the epithet aquifolium was used as a noun and it should be retained unchanged. Despite this newly discovered population some 100 kilometers away from its type locality, this species is still assessed as Critical Endangered (CR) according to the IUCN Red List Categories and Criteria.