Key points are not available for this paper at this time.
Sect. Tuberculata Chang in the genus Camellia (Theaceae Mirb.) is named after the “tubercle-like projections on the surface of the capsule and ovary”. Due to complex morphological variations in these taxon and insufficient field investigations, the interspecies relationships are unclear, the species’ definitions are vague, and the names are confusing. This is not conducive to the conservation and study of these species. Therefore, herein, we systematically explore the taxonomic status of five sect. Tuberculata species using morphological, pollen morphological, and molecular phylogenetic methods. The results showed that (1) the morphological characteristics of the flower, fruit, and leaves of C. anlungensis and C. leyeensis are similar. Furthermore, the pollen characteristics and pollen wall ornamentation show that there is no significant difference between the two species; (2) there are significant differences between C. acutiperulata and C. anlungensis in terms of leaf shape (elliptic vs. obovate), calyx characteristics (sepal apex pointed vs. sepal oblong), and fruit shape (subglobose folds with shallow verruculose vs. flat folds and verruculose protuberances with pronounced internal cleavage); (3) C. pyxidiacea and C. rubituberculata differ in flower color (white or light color vs. red) and fruit verrucae (obviously deeply cleft vs. shallowly uncracked); (4) a phylogenetic tree based on the chloroplast genome shows that C. anlungensis and C. leyeensis form a single clade (BS = 100%, PP = 1.0) and are on a different branch, with C. acutiperulata on clade II (BS = 100%, PP = 1.0), and C. pyxidiacea and C. rubituberculata clustered on different branches of clade I (BS = 99%, PP = 1.00). Considering the above results together, we propose that C. leyeensis should be treated as a homonym of C. anlungensis, and C. acutiperulata, C. pyxidiacea, and C. rubituberculata should be considered as separate species. Clarifying the taxonomic status of these five species not only advances our understanding of the significance and complexity of the systematic classification of the genus Camellia but also has important implications for diversity conservation and population genetics.
Xiao et al. (Sat,) studied this question.