Aster saxicola sp. nov. (Asteraceae, Astereae), a new species from Guizhou, China: evidence from morphological, molecular and cytological studies

Abstract

Aster saxicola W. P. Li & Z. Li, a new species of Asteraceae from southeastern Guizhou province, China, is described and illustrated based on morphological, molecular and cytological data. Morphological comparisons showed that A. saxicola is similar to A. oliganthus, but can be distinguished from the latter by its purple abaxial surface of the lower and middle cauline leaves, cordate‐ovate basal leaves with strigose hairs, outer three‐seriate phyllaries with purple or purplish apex, 9–14 ray florets and 10–18 disk florets. Phylogenetic analyses based on nrDNA ITS, ETS and plastid trnL–F DNA sequence data support that A. saxicola is a distinct species and belongs to Aster subgen. Aster sect. Ageratoides. Cytological observation shows that the new species is diploid with a karyotype formula 2n = 2x = 18 = 16m + 2sm. The new species should be considered endangered (EN) based on the IUCN red list criteria because of its restricted geographic range.