A Multivariate Morphometric Analysis of the Solidago chilensis Group in South America and Related Taxa in North America (Asteraceae, Astereae)1

A multivariate morphometric study of Solidago L. in South America was undertaken to assess the numbers and ranks of taxa that could be usefully recognized. The results of stepwise discriminant, classificatory, and canonical analyses on a matrix of 50 traits of 160 specimens indicated the distinctiveness of the S. chilensis group of taxa from three morphologically similar North American species of the large Solidago subsect. Triplinerviae (Torr. & A. Gray) G. L. Nesom: S. juliae G. L. Nesom, S. leavenworthii Torr. & A. Gray, and S. tortifolia Elliott. Within the South American complex two species with predominantly allopatric distributions were statistically supported: S. chilensis Meyen and S. microglossa DC. were distinguished a priori on stem hair length. The cytogeography of the two species was investigated and all samples were diploid, 2n = 18; S. chilensis (20 individuals from Argentina and one from Chile) and S. microglossa (six individuals from Argentina). Also, two other species of Solidago in South America that are not members of subsection Triplinerivae were found to have been misidentified as members of the S. chilensis complex; European S. virgaurea L. is a member of Solidago subsect. Solidago and native S. argentinensis Lopez Laphitz & Semple is a member of Solidago subsect. Junceae (Rydb.) G. L. Nesom. The name S. chilensis is neotypified.