Reconsideration of the Prunus serrulata complex (Rosaceae) and related taxa in eastern Asia.

摘要

The Prunus serrulata complex with several infraspecific taxa, including P. jamasakura and P. leveilleana, is indigenous to eastern Asia. Although these taxa are very common, the taxonomic confusion surrounding this complex is reflected in the ambiguity shown by the various taxonomic treatments currently used. Patterns of intraspecific variation and recognition of taxa within the P. serrulata complex and its related species were investigated in 468 individuals using principal components analysis. Particular emphasis was placed on P. serrulata, P. jamasakura, and P. leveilleana because of their high degree of morphological intergradation and inconsistent circumscription in the various systematic treatments. Although morphological variation among different taxa of the P. serrulata complex was continuous for most reproductive and leaf characters, the related taxa (P. pseudocerasus, P. lannesiana f. albida, and P. sargentii) were found to be distinct based on the number of flowers per inflorescence and peduncle length. In general, the number of flowers per inflorescence, the flower size, peduncle length, and hair density on the pedicel were found to be characters of great taxonomic value for most of the related taxa. However, there is not sufficient morphological evidence for the taxonomic splitting of P. serrulata to warrant the designation of varieties, with the exception of the pubescent taxon, P. serrulata var. pubesecens.