Populus × xiaohei T.S.Hwang & Y.Liang nothovar. xiaozhuanica (W.Y.Hsu & Y.Liang) C.Shang, 2016

Shang, Ce, Zhang, Limei & Zhang, Zhixiang, 2016, New combinations for nothotaxa of Populus (Salicaceae) from China, Phytotaxa 253 (2), pp. 176-178 : 177

Populus × xiaohei T.S.Hwang & Y.Liang nothovar. xiaozhuanica (W.Y.Hsu & Y.Liang) C.Shang comb. et stat. nov.

Basionym:— Populus × xiaozhuanica W.Y.Hsu & Y.Liang in Wang & Dong (1982: 107). Parental taxa: Populus nigra Linnaeus var. italica Münchhausen (1785: 79) × Populus simonii Carrière.

Type:— CHINA. Beijing: 1963. Liang Yan 1004 (holotype: CAF not seen) .

Populus × gansuensis and P. ×xiaozhuanica were described based on two artificial hybrids, and their hybrid formula were cited as P. nigra var. thevestina × P. simonii and P. nigra var. italica × P. simonii respectively. Both of the two names were in an inappropriate rank, since the rank of a nothotaxon should be the lowest rank of its parent taxa, if ranks of their parents are unequal (Art. H.5.2 of ICN). However, either of them may be nevertheless correct for P. nigra × P. simonii (Art. H.5.2 Note 1 and Ex. 1 of ICN). According to Art. H.4, only one name could be correct in the appropriate rank corresponding to a particular hybrid formula. Another name for a hybrid between P. nigra and P. simonii , P. × xiaohei was published in the same article, competing for the priority of P. nigra × P. simonii with P. × gansuensis and P. ×xiaozhuanica . Given that P. × xiaohei is a name in the appropriate rank, we propose two new combinations for P. × gansuensis and P. ×xiaozhuanica ( Fig. 1B ).

When P. × gansuensis was published, Yang Xi-Lin 79014 ♀ was cited as the type and two sheets of Yang Xi-Lin 79014 ♀ were found in LZD. According to the collecting record, the two specimens belong to the same gathering and should be treated as syntypes (Art. 9.5). With more mature leaves preserved well, LZD barcode 02727 is designated as the lectotype.

Figures

FIGURE 1. Correct names in the appropriate rank and their parentage for nothotaxa of Populus in Flora of China. A, P.×berolinensis = P. laurifolia × P. nigra, P.×berolinensis nothovar. berolinensis = P. laurifolia × P. nigra var. italica, P.×berolinensis nothovar. jrtyschensis = P. laurifolia × P. nigra var. nigra; B, P.×xiaohei = P. nigra × P. simonii, P.×xiaohei nothovar. xiaohei = P. nigra var. nigra × P. simonii, P.×xiaohei nothovar. gansuensis = P. nigra var. thevestina × P. simonii, P.×xiaohei nothovar. xiaozhuanica = P. nigra var. italica × P. simonii.