Leaf anatomy of Camellia sect. Oleifera and sect. Paracamellia (Theaceae) with reference to their taxonomic significance

Leaf anatomy of 21 species representing sect. Oleifera H. T. Chang and sect. Paracamellia Sealy in the genus Camellia was investigated using light microscopy. All the shapes of leaf epidermal cells were polygo-nal, and the patterns of anticlinal walls were sinuolate or sinuous, which were important to the classification of these two sections. The stomata were cyclocytic type and only present on the abaxial epidermis in both sampled sections. Seventeen leaf anatomical and cytologic characters were selected and used for the cluster analysis and principle components analyses performed by PAST program. Congruent results were obtained, with sect. Oleifera and sect. Paracamellia consistently grouping in two different clades, and some related species nesting together. This study provided leaf anatomical evidence for the merge of C. lanceoleosa H. T. Chang & J. S. Chiu and C. fluviatilis Hand.-Mazz.; of C. brevistyla Coh. St., C. obtusifolia H. T. Chang, and C. puniceiflora H. T. Chang; and of C. grijsii Hance and C. shensiensis H. T. Chang. In addition, it was also proved that C. tenii Sealy should be segregated from sect. Paracamellia and placed in the sect. Corallina Sealy. For further interest, we suggested that C. phaeoclada H. T. Chang be recognized as a subspecies of C. microphylla (Merr.) Chien. Overall, the results presented provided new insights into the relationships within a number of Camellia plants and sug-gested directions for future studies.