Sinosenecio yaanensis (Asteraceae, Senecioneae), a new species from western Sichuan, China

<i>Sinosenecio yaanensis</i> K.Huang & Z.X.Fu (Asteraceae) is described as a new species from Tianquan County, western Sichuan, China. It resembles <i>S. chienii</i> and <i>S. homogyniphyllus</i> in its scapigerous habit and palmately veined ovate to ovate-cordate radical leaves, but differs in several stable traits. Its leaves are subcoriaceous with whitish blotches adaxially and a purplish red abaxial surface, whereas <i>S. chienii</i> has submembranous blades that are pale green on the abaxial surface, while <i>S. homogyniphyllus</i> has smaller membranous leaves. <i>Sinosenecio yaanensis</i> produces 3-10 (vs. 2-9 in <i>S. chienii</i> and mostly solitary in <i>S. homogyniphyllus</i>) capitula, ca. 8 (vs. 10-12 and 8-17) ray florets, and lacks a pappus (vs. absent or rarely with short hairs). Phylogenetic analyses based on chloroplast genomes and ITS sequences place <i>S. yaanensis</i> within the <i>Sinosenecio</i>-tussilaginoid assemblage corresponding to the Tussilagininae subtribe, clustering with <i>S. chienii</i> and <i>S. homogyniphyllus</i>.