Sorbus arguta T.T. Yu, Acta Phytotax. Sin. 8(3): 223. 1963.

Chen, Xin, Ma, JianHui & Geng, LiYang, 2022, Taxonomic notes on Sorbus megalocarpa (Rosaceae) and related taxa, PhytoKeys 201, pp. 131-138 : 131

2. Sorbus arguta T.T. Yu, Acta Phytotax. Sin. 8(3): 223. 1963.

Micromeles arguta ≡ Micromeles arguta (T. T. Yu) Mezhenskyj, NULESU Coll. Fruit Ornament. Pl.: 33. 2018.

Wilsonaria arguta ≡ Wilsonaria arguta (T. T. Yu) Rushforth, Phytologia 100(4): 241. 2018.

Aria yuarguta = Aria yuarguta H. Ohashi et Iketani, J. Jap. Bot. 68(6): 361. 1993.

Type.

China. Sichuan: Pingshan, Chingping Shan , 1120 m, 26 May 1934, T.H. Tu 5449 (holotype: PE[PE00934274]; isotype: PE[PE00934275])

Notes.

When describing Sorbus arguta , Yü designated " T. H. Tu 5449 " at PE (Fig. 2B ) as the holotype ( Yü and Kuan 1963). It was accepted by Yü and Lu (1974), Gabrielian (1978), Phipps et al. (1990) and Lu and Spongberg (2003). Ohashi and Iketani (1993) transferred it to genus Aria and proposed a new name A. yuarguta H. Ohashi et Iketan (Ohashi and Iketan 1993: 361) for A. arguta had been already used by Roemer in 1847 for a different species. Mezhenskyj transferred it to Micromeles ( Mezhenska et al. 2018: 33) and Rushforth (2018: 241) transferred it to Wilsonaria .

However, Aldasoro et al. (2004) argued that: " S. arguta is a minor variant of S. megalocarpa and does not deserve taxonomic recognition ", and reduced it to a synonym of the later. A detailed study of the original material showed that Sorbus arguta is obviously different from S. megalocarpa . Sorbus arguta has oblong-ovate or ovate-lanceolate leaves with double serrate margins, relatively small corymbs (2-4 cm in diameter) with few flowers, and small sub-globose fruits (1-1.2 cm in diameter) with sparse lenticels, while S. megalocarpa has leaves with crenate-serrate margins, large corymbs (10-15 cm in diameter), many flowered (124-258 flowers per inflorescence), and much larger fruits with dense lenticels. Furthermore, S. arguta flowers after leaves are unfolded in early May (Fig. 3A , CBDI0226241), whereas S. megalocarpa flowers simultaneously with or before the leaves are unfolded in March (Fig. 3B, C ). Therefore, S. arguta is treated as a distinct species here following Yü and Lu (1974), Gabrielian (1978), Phipps et al. (1990) and Lu and Spongberg (2003).

Representative specimens examined. China. Sichaun: Xinwen county, Xianfeng town, Monkey Bay, 1290 m, 12 May 1959, Yibin wild economic plants collection team 0368 (CDBI); Xuyong county, Heishuihe Nature Reserve, 1500 m, 6 June 2007, D.H. Zhu, Z.B. Feng, C. Zhang, F. Wang 20070776 (WCSBG); Xuyong county, Shuiwei town, Xixi village, 28°09'00"N, 105°20'40"E, 1100 m, 7 May 2014, L. Zhang, X.M. Zhou, W.B. Ju HGX14304 (CDBI); Xuyong county, Shuiwei town, Xixi village, 28°08'01"N, 105°22'20"E, 1230 m, 29 July 2014, W.B. Ju HGX14833 (CDBI).

Figures

Figure 2. A holotype of Sorbus guanxianensis Ku (PE 00020830) B holotype of Sorbus arguta T. T. Yu (PE 00934274).

Figure 3. Corymbs of Sorbus arguta and S. megalocarpa A flowering specimen of Sorbus arguta (CBDI 0226241) collected by Liang Zhang, Xinmao Zhou and Wenbin Ju, 7 May 2014 B Sorbus megalocarpa at blossoming stage, 21 March 2021 C detail of the inflorescence of S. megalocarpa (B, C were taken by Tailun Hu).