Pternopetalum paucifoliolatum (Apiaceae), a new Critically Endangered species from Sichuan, China

Pternopetalum paucifoliolatum, a new species from Sixigou Scenic Area, Emeishan City, Sichuan Province, is proposed and described. Diagnostic morphological characters, full description, detailed illustrations, and a distribution map are provided. The new species is similar to P. porphyronotum in possessing the 1-pinnate leaves and the abaxially purple-red leaflets, but differs from the latter by shorter stature, fewer leaflets ((1–) 3–7) and rays (5–8), the leaflet margin white-ciliate. The new species, which is assessed as Critically Endangered (CR), was only found on limestone cliffs. We also provide a new key to the species of Pternopetalum.