Youngia is a genus of flowering plants in the family Asteraceae (the daisy family), placed within the tribe Cichorieae and the order Asterales. The genus comprises primarily Asian species and includes both weedy, widespread taxa and more narrowly endemic ones. Among its members is Youngia japonica, commonly known as Japanese hawkweed, a widely distributed weed across Asia and introduced elsewhere, and Youngia nilgiriensis, an endangered species restricted to the Sispara area of the Nilgiri Hills in southern India.
The genus was first described in 1831 by the French botanist Henri Cassini. It was subsequently merged with the closely related genus Crepis, but detailed taxonomic and cytogenetic investigations carried out in the 1930s by E. B. Babcock and G. Ledyard Stebbins demonstrated sufficient distinctions to reinstate Youngia as a separate genus. Like other members of Cichorieae, Youngia species produce composite flower heads (capitula) composed exclusively of ligulate (strap-shaped) florets, a characteristic feature of this tribe within Asteraceae.
Etymology
The genus name Youngia honours a person named Young; the precise dedicatee has not been specified in the primary literature summarised for this entry, as Cassini's original 1831 description details are not widely restated.
Distribution
Youngia is centred in Asia, with species distributed across East, South, and Southeast Asia. Youngia japonica (Japanese hawkweed) is one of the more widespread species in the genus. Youngia nilgiriensis has a highly restricted range, known only from Sispara in the Nilgiri Hills of southern India.
Taxonomy Notes
Youngia was first described by the French botanist Henri Cassini in 1831 and was subsequently subsumed into the closely related genus Crepis. Taxonomic and cytogenetic work by E. B. Babcock and G. Ledyard Stebbins in the 1930s demonstrated sufficient distinctions to reinstate Youngia as a separate genus. GBIF places the genus in the tribe Cichorieae, family Asteraceae, order Asterales, class Magnoliopsida.
