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| Pulvinatusia xuegulaensis J. P. Yue, H. L. Chen, Al-Shehbaz & H. Sun, in Chen, Al-Shehbaz, Qian, ... et Sun, 2022. |
Abstract
The new genus and species Pulvinatusia xuegulaensis (Brassicaceae) are described and illustrated. The species is a cushion plant collected from Xuegu La, Xizang, China. Its vegetative parts are most similar to those of Arenaria bryophylla (Caryophyllaceae) co-occurring in the same region, while its leaves and fruits closely resemble those of Xerodraba patagonica (Brassicaceae) from Patagonian Argentina and Chile. Family-level phylogenetic analyses based on both nuclear ITS and plastome revealed that it is a member of the tribe Crucihimalayeae, but the infra-/intergeneric relationships within the tribe are yet to be resolved.
Keywords: Crucihimalayeae, cushion plants, molecular phylogenetics, new species, Xizang
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| Images of Pulvinatusia xuegulaensis A and B fruiting plants C fruits D septum and replum E and F seeds G and H flowering plants I and J stems K leaves. Scales bars: 1 mm. Photos: A–F & I–K by Lishen Qian G and H by Jianwen Zhang. |
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| Habitat and geographic distribution of Pulvinatusia xuegulaensis A–C alpine meadow habitat, white arrow in A points to the location, white arrows in B and C point to P. xuegulaensis Photos: A by Jianwen Zhang B and C by Lishen Qian. |
Pulvinatusia J.P. Yue, H.L. Chen, Al-Shehbaz & H. Sun, gen. nov.
Pulvinatusia xuegulaensis J. P. Yue, H. L. Chen, Al-Shehbaz & H. Sun, sp. nov.
Diagnosis: As indicated above, the monospecific Pulvinatusia xuegulaensis and Ladakiella klimesii are the only members of the tribe Crucihimalayeae with pulvinate and scapose habit and pink to whitish pink petals. The former differs by having simple and fewer forked trichomes, thin papery leaves, solitary flowers, caducous sepals, and glabrous, somewhat flattened fruits. By contrast, L. klimesii has subdendritic trichomes with finely branched rays, thick and fleshy leaves, 2–4-flowered racemes, persistent sepals, and pubescent and terete fruits.
Name derivation: The generic name is derived from the pulvinate habit of the plant, and the species epithet from the Xuegu La (Xizang, China), where the type collection was made.
Hong-Liang Chen, Ihsan A. Al-Shehbaz, Li-Shen Qian, Jian-Wen Zhang, Bo Xu, Ti-Cao Zhang, Ji-Pei Yue and Hang Sun. 2022. Pulvinatusia (Brassicaceae), A New cushion Genus from China and its systematic position. PhytoKeys. 189: 9-28. DOI: 10.3897/phytokeys.189.77926
