A new species of Youngia (Asteraceae, tribe Cichorieae) from Yunnan, China

Abstract

Youngia gongshanensis, a new species of Youngia sect. “Mesomeris” from Yunnan province of China is described and illustrated based on evidence from morphology and molecular phylogeny. The new species is superficially very similar to Y. atripappa having a solitary and erect stem and more or less lyrately pinnatisect leaves, but can be distinguished by capitula with 5–6 (vs. 12–15) florets, corolla tube glabrous (vs. sparsely pubescent with short white spreading hairs), pappus white (vs. grayish), bracts ovate to elliptic, distinct large (vs. very small, subulate). Parsimony analyses based on DNA sequence data of the nuclear ribosomal ITS shows that the new species is sister to Y. cineripappa with strong support, but the new species differs from the latter in having a glabrous corolla tube, smaller capitula with a lesser number of florets, and especially the white pappus.

Micromorphological and cytological comparisons between Youngia japonica and Youngia longiflora using light and scanning electron microscopy

“…The examined micromorphological characters have provided diagnostic characters for taxonomic delineation of species in other Asteraceae taxa (Ayaz et al, 2019; Dere & Akcin, 2017; Karanović et al, 2015; Sonboli et al, 2013; Yuan, Bi, & Chen, 2015) and may be driven by differing ecological conditions (Haworth & McElwain, 2008). Our results confirmed that the pappus is directly joined to the pericarp in the investigated species, in agreement with other species in the genus (Ke & Chen, 2016; Peng et al, 2014; Figures 1j and 2j).…”

“…Scale bar = 5 μm. Arrows indicate nucleolar organizer regions (NORs) pericarp in the investigated species, in agreement with other species in the genus (Ke & Chen, 2016;Peng et al, 2014;Figures 1j and 2j).…”

“…Despite the increasing number of new species reports in the genus Youngia (Cai et al, 2019; Chen, 2018; Deng et al, 2014; Ke & Chen, 2016; Peng, Gao, & Zhang, 2017; Peng et al, 2015), taxonomic and evolutionary studies based on detailed micromorphological and cytological approaches, using LM and SEM, are still sparse in the genus. Only pollen and cypselae morphology has been explored in any detail in a limited number of taxa, but never in both Y. japonica and Y. longiflora .…”

“…Species of the genus Youngia are annual, biennial, or perennial herbs, usually growing up to 10 to 150 cm tall and characterized by oblanceolate to pinnatipartite basal leaves, ovate to elliptic lateral lobes, a corymbiform to paniculiform synflorescence head, 10 to 20 yellowish florets, and a brown to dark reddish fusiform achene (Pak & Yang, 2017; Shih & Kilian, 2011). The center of species diversity is in China, where new Youngia species have been recently described (Cai et al, 2019; Chen, 2018; Deng et al, 2014; Ke & Chen, 2016; Peng et al, 2015, 2017). Only two, morphologically similar species, Youngia japonica (L.) DC.…”

Lihengia: A new genus of Asteraceae distinct from Dubyaea

“…Both cypselas and pollen material were collected from plants in the wild or from herbarium specimens. Sixty‐four samples were chosen for the molecular phylogenetics, representing the main clades of tribe Cichorieae resolved in published phylogenetic trees (Liu & al., 2013; Ke & Chen, 2016), and 20 samples representing 11 species of Dubyaea (Appendix 1). All voucher specimens were deposited in PE and IBSC.…”