8751.000 Vernonia Schreb.

Annual or perennial herbs (often with annual stems from woody rootstocks), small to large shrubs, woody scramblers or small trees. Leaves alternate, simple. Capitula homogamous, discoid; florets normally bisexual and fertile. Phyllaries free in 2-many series, imbricate. Corolla various shades of purple, blue, or creamy-white, regularly 5-lobed. Pappus 2-seriate with an outer short whorl of scales or setae and an inner whorl of longer setae.

Derivation of name: Named after William Vernon, English botanist of the late 17th century.

Comment: Studies, since the 1970s, based on chromosome counts, chemistry, pollen and DNA, have shown that the genus Vernonia is paraphyletic with two centres of origin, one in S America and one in Africa and SE Asia (Herman & Swelankomo, 2011).

Based on these studies, a number of segregate genera have been proposed for African species of Vernonia. To date, this process is not complete and for the time being we have retained the use of the genus Vernonia, but have added the new genus and species names as synonyms in cases where these are known to us.

Worldwide: c. 500 species in warm and tropical regions of the Old World and America