Parasenecio chenopodifolius (Compositae-Senecioneae) is a Synotis and conspecific with S. otophylla based on evidence from morphology, cytology, and ITS/ETS sequence data
10 June 2014
Tang, Ming; Ren, Chen; Yang, Qin-erObservations on living plants and herbarium specimens have convinced us that Synotis otophylla (Compositae-Senecioneae) from south Xizang (Tibet), China, must be merged with the Himalayan Parasenecio chenopodifolius. However, is the plant a Synotis or a Parasenecio? We have examined floral micromorphological and cytological characters of P. chenopodifolius, and performed molecular phylogenetic analyses based on ITS and ETS sequence data. The anther collar of this taxon is balusterform, and the endothecial tissue cell wall thickenings are radial. These conform to the floral microcharacters of Synotis but differ from those of Parasenecio, which has subcylindrical anther collars, and polarized endothecial tissue cell wall thickenings. Chromosomes counts indicate the taxon has 2n = 40, a number common in Synotis; Parasenecio has 2n = 60. Our phylogenetic analyses based on ITS/ETS sequences also place P. chenopodifolius in Synotis. We propose the new combination S. chenopodifolia and synonymize S. otophylla.