In: Phyton 58, Fasc. 2 (2018): S. 185-204 DOI: 10.12905/0380.phyton58(2)-2019-0185 Published online on 31st January 2019

Taxonomic novelties in the genus Spiraea (Rosaceae-Amygdaloideae-Spiraeeae) in Asia

Roman Businský

Key words: Rosaceae, Spiraea, Spiraea sericeoides spec. nova, S. cardotiana spec. nova, S. wilsonii var. stenophylla var. nova, S. turczaninowii nom. nov. – Taxonomy, synonymy, typifications. – Flora of China and adjacent countries.

Summary
Businský R. 2019. Taxonomic novelties in the genus Spiraea (Rosaceae-Amygdaloideae-Spiraeeae) in Asia. – Phyton (Horn, Austria) 58 (2): 185–204, with 6 figures.*

The present study deals with several independent taxonomic issues of the genus Spiraea in eastern and southeastern Asia. Two new species are described from central China. Spiraea sericeoides Businský, distributed from southern Shanxi to central Sichuan, is segregated from S. sericea (confirmed only from the Russian Far East, northeastern China, North Korea, and northern Japan), and it is compared to the enigmatic S. pjasetzkii (syn. S. prostrata Maxim., nom. illeg.), which is known only from the syntype collections from 1875. Spiraea sericea is accepted here only at the rank of variety, as S. media var. sericea (Turcz.) Maxim. The other new species, Spiraea cardotiana Businský, narrowly endemic at the eastern margin of the Tibetan Plateau in western Sichuan, was collected sporadically (provably in 1893, 1908, 1992, and 2007) because its diagnostic trait (distinctly heteromorphic leaves) has been overlooked due to the usual incomplete herbarium collections. Spiraea canescens var. oblanceolata Rehder is newly synonymized with S. cardotiana. Spiraea cardotiana is allied to S. canescens and S. schneideriana, which are delimited morphologically and geographically in this paper. The occurrence of S. canescens in the Chinese provinces Yunnan and Sichuan cannot be supported by any reliable collection. The hitherto almost unknown S. wardii, confined to two collections from northern Burma from 1914 and 1919, is newly synonymized with S. canescens. Other anomalous collections from Sichuan and Yunnan assigned incorrectly to S. canescens are commented upon, and the similar S. schochiana is typified by the newly designated lectotype. Spiraea hemicryptophyta, described from the eastern Himalayas and adjacent ranges to northwestern Yunnan, is newly synonymized with the two years older and forgotten S. subrotundifolia; the holotype specimens of both names were collected in Sikkim. The recently described S. fangii, known from a single locality at the eastern margin of the Tibetan Plateau west of Chengdu in Sichuan, is accepted as an ecological form of S. alpina and is newly synonymized with it (S. alpina occupies a large distribution area in high mountains from southern Siberia and Central Asia across the Tibetan Plateau to central China). Spiraea wilsonii, described in 1906 based on the collection of E. H. Wilson from northwestern Hubei in central China and occasionally misinterpreted in herbaria, is stabilized by the newly designated lectotype, and S. uratensis var. floribunda is newly synonymized with it. A new variety, S. wilsonii var. stenophylla Businský, is described based on the type of S. longifolia H. Y. Hu & X. J. He (nom. illeg.). The newly designated lectotype of S. flexuosa, fully corresponding to the protologue, was selected from the holdings of herbarium P (M.N.H.N., Paris), instead of the previously accepted but not representative “typus” in herbarium G (C.J.B., Chambésy/Geneva); this taxon is accepted here as S. chamaedryfolia var. flexuosa. A new name, S. turczaninowii Businský, is proposed for the illegitimate S. pubescens Turcz., together with the newly designated