Morphological and cytological data support the independent specific status of Parasenecio delphiniphyllus (Asteraceae-Senecioneae) from China
23 November 2014
Yang, Qin-erThe identity of Parasenecio delphiniiphyllus (Asteraceae-Senecioneae), a species distributed in northeastern Yunnan and western Guizhou, China, has long been a controversial matter. Most authors recognized it as an independent species, but some placed it in the synonymy of the Japanese species P. delphiniifolius because of the great resemblance in leaf shape as indicated by their specific epithets. Our morphological observations indicate that the two species are readily distinguishable from each other in inflorescence structure and involucre length. Floral micro-morphological observations reveal that they are distinct in the length of anther-tails and of anther-collars. Most importantly, our cytological examination shows that P. delphiniiphyllus has the chromosome number of 2n = 60, not 2n = 52 in P. delphiniifolius. Evidence from gross-morphology, floral micro-morphology, cytology and geographical distribution, therefore, all strongly supports the independent specific status of Parasenecio delphiniiphyllus.