Abstract
Sinoseneciominshanicus (Asteraceae, Senecioneae), a new species from south-eastern Gansu (Wenxian and Zhugqu counties) and northern Sichuan (Pingwu county), China, is described and illustrated. This species is similar to S.rotundifolius, a species locally endemic to Songpan county in northern Sichuan, in having a scapigerous habit, orbicular leaves and solitary capitula, but differs by the presence (vs. absence) of stolons and by having thinner rhizomes (ca. 2 mm vs. more than 5 mm in diameter), stems proximally sparsely fulvous arachnoid or glabrescent (vs. densely sericeous-villous) and obscure (vs. conspicuous) main veins on adaxial surface of leaves. The chromosome number of the new species is reported to be 2n = 60. Colour photographs of living plants in the wild and a distribution map are provided for the new species and S.rotundifolius. The geographical distribution of S.rotundifolius is also corrected, with the previous record of this species from south-eastern Gansu (Wenxian county) actually referring to S.minshanicus.