Petal pigment compositions were used as markers to study the phenetic relat
ionships among seven wild tree peony species of Paeonia section Moutan DC.
(fifteen accessions) from China. As the pigment markers, five anthocyanins
together with three flavone and three flavonol aglycones were used. Princip
al component analysis (PCA) provided five eigenvectors from nineteen pigmen
t patterns, in which peonidin and cyanidin as well as the types of glycosid
es; greatly influenced the first factor, Zi. The Euclidean distances of sta
ndardized values obtained by eigenvector matrices with five factors (Z(1) t
o Z(5)) produced a dendrogram in Ward's minimum variance cluster analysis,
which showed good agreement with a classification based on the morphologica
l characteristics of two subsections Vaginatae F.C. Stern and Delavayanae F
.C. Stern. The results obtained by PCA and clustering quality a chemical cl
assification of section Moutan using secondary metabolites, specifically fl
ower pigments, as taxonomic markers.