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| Hedysarum qilianshanense P.L.Liu, in Liu, Guo, Zhang, Xun, Lu et Yue, 2024. |
Abstract
Hedysarum qilianshanense sp. nov. (Fabaceae, Hedysareae) is described and illustrated from the Qilianshan Mountains in Gansu, China. This new species is similar to H. przewalskii, but can be distinguished by its corolla being light purple to purple, standard 15–19 mm long, wings 14–16 mm long, keels 16–19 mm long, and the ovary and legume being glabrous. The new species can be easily distinguished from H. neglectum Ledeb. by its bract being shorter than the pedicel, and the ovary and legume being glabrous. Phylogenetic tree based on the nuclear ITS and ETS sequences shows that H. qilianshanense is sister to H. przewalskii, while the tree based on the plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences shows H. qilianshanense as sister to a clade consisting of H. hedysaroides, H. inundatum, H. americanum and H. neglectum. The new species is a diploid with the chromosome number 2n = 14. Based on morphological, phylogenetic and karyotypic evidence, the new species may originate from an ancient homoploid hybrid speciation event.
Key words: Karyotype, phylogeny, Qinghai-Tibetan Plateau, taxonomy
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| Illustration of Hedysarum qilianshanense a root and basal part of stems b upper part of plant c calyx tube (split between an adaxial tooth and a lateral tooth) d bracteoles e standard f wing g keel h androecium i pistil j infructescence k legume. Drawn by Xiu-Zhen Wu. |
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| Photos of Hedysarum qilianshanense from the field A habitat B plant C raceme D infructescence. Photographed by Pei-Liang Liu. |
Hedysarum qilianshanense P.L.Liu, sp. nov. (H. sect. Hedysarum)
Diagnosis: This new species is morphologically similar to H. przewalskii, but can be distinguished by its light purple to purple corolla (vs. light yellow to yellow corolla), 15–19 mm long standard (vs. 10–14 mm long standard), 14–16 mm long wings (vs. 10–14 mm long wings), 16–19 mm long keels (vs. 12–17 mm long keels), and glabrous ovaries and legumes (vs. often pubescent, sometimes glabrate or glabrous ovaries and legumes). The new species can be easily distinguished from H. neglectum by its bract shorter than pedicel (vs. bract longer than pedicel), and glabrous ovaries and legumes (vs. pubescent ovaries and legumes) (Table 2).
Distribution and habitat: Hedysarum qilianshanense is only known from Su’nan, Gansu, China. It grows in stony slope and forest edge in valley, 2053–3000 m a. s. l.
Etymology: The epithet qilianshanense is transliterated from the type location, Qilianshan Mountains in China. The Chinese vernacular name for this new species is 祁连山岩黄耆 (qí lián shān yán huáng qí).
Pei-Liang Liu, Qian-Xi Guo, Jian-Qi Zhang, Lu-Lu Xun, Yuan Lu and Ming Yue. 2024. Hedysarum qilianshanense sp. nov. (Fabaceae, Hedysareae), A New Species from the Qilianshan Mountains in Gansu, China. PhytoKeys. 237: 103-116. DOI: 10.3897/phytokeys.237.116236
