On the correct subtribal placement of the genera Syreitschikovia and Nikitinia (Asteraceae, Cardueae): Carduinae or Centaureinae?

Abstract

The limits between subtribes Carduinae and Centaureinae (Asteraceae, Cardueae) are well established. However, the most suitable characters for separating both subtribes are the achene and pappus characters, which are often very difficult to observe in immature herbarium material, and this has often been a source of misclassifications. We have examined two examples, the genus Nikitinia, usually classified among the Carduinae, and the genus Syreitschikovia, placed in the Centaureinae. A study of pappus characters demonstrates that both genera have been misplaced: Nikitinia should be classified in the Centaureinae and Syreitschikovia in the Carduinae. A description of both genera, together with some considerations as to their nomenclature and distribution, is also provided. © The Linnean Society of London.