Populus × berolinensis K.Koch nothovar. jrtyschensis (Chang Y.Yang) C.Shang comb. & stat. nov.

Basionym:— Populus × jrtyschensis Chang Y.Yang in Wang & Dong (1982: 112). Parental taxa: Populus laurifolia Ledebour × Populus nigra Linnaeus var. nigra .

Type:— CHINA. Xinjiang Uygur Autonomous Region: Ertix River, Beitun, s. dat, Yang Chang-you 755787 (holotype: XJA not seen) .

Populus × jrtyschensis was described for a natural hybrid species distributed aside Ertix River. While the name was originally published, the multiplication sign ‘×’ was added ahead of the epithet (Wang & Dong 1982), declaring its hybridity. Its parents were then indicated to be P. laurifolia and P. nigra based on the transitional morphology characters between putative parent species (Yang 1992, 2012), and molecular evidence supporting this hypothesis was provided from a DNA barcode research (Feng et al. 2013). However, the parentage statement of P. × jrtyschensis would make it a synonym of P. × berolinensis . Populus × berolinensis was described from Berlin and was thought to be a hybrid between P. laurifolia and P. nigra var. italica . Although it is in a rank inappropriate in relation to that hybrid formula (Art. H.5.2 of ICN), P. × berolinensis is nevertheless the correct name applicable to all hybrids between P. laurifolia and P. nigra (Art. H.5 Note 1 and Ex. 1 of ICN). Hence we propose a new combination for P. × jrtyschensis (Fig. 1A).