NOVON 9(3): 453. 1999.
Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
Abstract. Three new subspecific combinations are proposed in the genus Kobresia: K. myosuroides (Villars) Fiori subsp. bistaminata (W. Z. Di & M. J. Zhong) S. R. Zhang, K. royleana (Nees) Boeckeler subsp. minshanica (Wang & Tang ex Y. C. Yang) S. R. Zhang, and K. setschwanensis Handel-Mazzetti subsp. squamaeformis (Y. C. Yang) S. R. Zhang. Additionally, K. kashgarica Dickoré is treated as a synonym of K. myosuroides subsp. bistaminata and K. menyuanica Y. C. Yang as a synonym of K. royleana subsp. minshanica.
In preparing the account of Kobresia for the forthcoming volume of Flora of China, the following new combinations have been found necessary.
Kobresia myosuroides (Villars) Fiori subsp. bistaminata (W. Z. Di & M. J. Zhong) S. R. Zhang, comb. nov. Basionym: Kobresia bistaminata W. Z. Di & M. J. Zhong, Acta Bot. Bor.-Occid. Sin. 6: 275. 1986. TYPE: China. Nei Mongol: Helanshan, Halawugou, 25 July 1984, EHNWU [Northwest University Expedition to Helanshan] 6051 (holotype, WNU).
Kobresia kashgarica Dickoré, Stapfia, 39: 79. 1995. Syn. nov. TYPE: China. Xinjiang: Kunlun Shan, Tiznap, tributary valley W of Kudi, 36° 51'N, 76° 57'E, 4040 m, 9 July 1992, G. & S. Miehe 8471 (holotype, K; isotypes, GOET, PE).
Kobresia myosuroides is widespread in the Northern Hemisphere, with a range extending from northern China to the Arctic region. Plants of northwestern China (from western Nei Mongol to western Xinjiang), which were described as K. bistaminata and K. kashgarica and treated here as the subspecies bistaminata, differ from those of the rest of the species range in having slightly smaller (2.5--3.5 mm long) glumes with a narrowly hyaline or not hyaline margin and smaller nuts 1.8--2.3 mm long. In contrast, subspecies myosuroides has glumes (2--)3--4 mm long with a broadly hyaline margin and nuts 2--2.8 mm long.
Kobresia royleana (Nees) Boeckeler subsp. minshanica (Y. C. Yang) S. R. Zhang, comb. nov. Basionym: Kobresia minshanica Wang & Tang ex Y. C. Yang, Acta Biol. Plateau Sin. 2: 1. 1984. TYPE: China. Gansu: Minxian, 10 Aug. 1978, J. Q. Wang 228 (holotype, NWTC).
Kobresia menyuanica Y. C. Yang, Acta Biol. Plateau Sin. 2: 3. 1984. Syn. nov. TYPE: China. Qinghai: Menyuan, 6 Sep. 1980, X. M. Zhou 273 (holotype, HNWP).
Kobresia royleana is distributed in the central Asian highlands and Himalayas. Plants of subspecies minshanica, which are restricted to eastern Qinghai and Gansu, are rather slender and often have unisexual lateral spikelets with one female flower, whereas those of subspecies royleana are stout and have bisexual lateral spikelets with a basal female flower and several distal male flowers.
Kobresia setschwanensis Handel-Mazzetti subsp. squamaeformis (Y. C. Yang) S. R. Zhang, comb. nov. Basionym: Kobresia squamaeformis Y. C. Yang, Acta Biol. Plateau Sin. 2: 9. 1984, sphalm. "squmaeformis." TYPE: China. Gansu: Xiahe, 3300--3600 m, 14 Aug. 1980, H. T. Zhao s.n. (holotype, LZU).
In the protologue of Kobresia squamaeformis, the species was considered similar to K. pygmaea C. B. Clarke and K. bellardii (Allioni) Degland (= K. myosuroides). I have studied the type specimen of K. squamaeformis and have seen it in the field in Zeku, Qinghai. It is most closely related to K. setschwanensis. Although the taxon is distinguishable from K. setschwanensis on the basis of basal sheaths, glumes, prophylls, and nuts, it can be distinguished by being shorter (7--16 cm) and having unbranched inflorescences 8--12 mm long and unisexual or sometimes bisexual lateral spikelets with a basal female flower and a distal male flower. In contrast, K. setschwanensis is taller (10--40 cm high) and often has basally branched inflorescences 20--25 mm long and bisexual spikelets with a basal female flower and (1)2--6 distal male flowers. Subspecies squamaeformis is distributed in eastern Qinghai and adjacent Gansu, while subspecies setschwanensis occurs in southern Qinghai, Sichuan, Yunnan, and Xizang (Tibet).
Acknowledgment. I thank Ihsan Al-Shehbaz for his help with the manuscript.