Taxonomic reconsideration
Cerasus serrulata , a complex with ample variations and transition phenotypes some of which are morphologically specialized in the process of diversification by specific environments, has brought about taxonomic controversies. Here, C. xueluoensis , published in 2013 (Nan et al., 2013), treated as an outgroup in this study, was totally mixed up with haplotypes or ribotypes of C. serrulata in cladograms built by both cpDNA and ITS sequences (Figure 3, Figure 6). To further discuss the relationship between C. xueluoensis and C. serrulata , more wild related species were added to rebuild the cladograms based on ITS sequences. This time, C. xueluoensis was separated from the clade formed by all ribotypes of C. serrulata (Figure 9). However, more adequate and accurate information is needed to define the interrelationship between C. xueluoensis and C. serrulata .
Interestingly, C. serrulata var. lannesiana was significantly detached from C. serrulata in this tree (Figure 9), supporting its treatment as C. lannesiana . C. laoshanensispublished in 2017 was described to resemble C. serrulata (Zang, 2017). Nevertheless, population LaoS in this study representing C. laoshanensis , showed no specificity from C. serrulataindividuals in any relationship analysis. Thus, it was endorsed to mergeC. laoshanensis into C. serrulata . Besides, C. huangangensis , a record in 2007 (Yi, 2007), represented by population HGS which showed distinctiveness as exclusively possessed only one kind of haplotype or ribotype both in cpDNA and ITS (Figure 1, Figure 4), also within the big clade in both trees of C. serrulata , is ought to treated as C. serrulata var. huangangensis .