Hieracium radyrense
Hieracium radyrense, the Radyr hawkweed, is a very rare endemic species restricted to Radyr in south Wales, UK. First identified in 1907 it was described as a variety in 1948 and a species in 1955. and belongs to Hieracium section Vulgata. It has rarely been seen and surveys between 1998 and 2004 indicate that only one population of about 25 plants survives.
A polycarpic perennial, Radyr hawkweed flowers from late May to early June or July. Specimens found at Danybryn in Radyr grew on a grassy bank and lawn under the partial shade of trees and shrubs.