Hieracium lachenalii also known as common hawkweed or yellow hawkweed is a species of plants in the dandelion tribe within the sunflower family. It is native to Europe but has become established as a weed in Australia and parts of North America. The species was widely known for many years as H. vulgatum but more recent studies indicated that the two names represented the same species. The name H. lachenalii was coined in 1802, H. vulgatum in 1819, so the older name is to be used.