The genus Solidago L. (Astereae, Asteraceae) in South America and related taxa in North America

Abstract

The goldenrod genus Solidago L. is one of the larger genera in the flowering plant family Asteraceae. The genus is primarily North American and was recently revised in Flora of North America. In contrast, Solidago in South America is not well understood and has been thought to be represented by one group in one subsection the S. chilensis complex with only two species. However, among specimens borrowed to analyze the Solidago chilensis complex were a small number of collections of two additional species, S. missouriensis Nutt. and S. virgaurea [synonym: S. patagonica], from two different subsections not previously reported from South America. Using multivariate morphometric analyses on a matrix of 50 traits of 160 specimens (stepwise discriminant, classificatory and canonical analyses), the distinctiveness of the Solidago chilensis complex was tested and found to be statistically different from three morphologically similar North America species. Using just the 104 specimens of the Solidago chilensis complex, the previously published classification dividing the complex into two species was tested and found to be supported statistically but with many misclassifications a posteriori. Alternative ways of dividing the complex into species and varieties were explored in order to create a statistically strongly supported revised classification of the Solidago chilensis complex with two species, S. chilensis and S. microglossa.