A multivariate morphometric analysis of Solidago subsect. Glomeruliflorae (Asteraceae: Astereae)

Abstract

A multivariate morphometric study of Solidago subsection Glomeruliflorae (Torr. & A. Gray) Nesom was undertaken on a matrix of 45 characters by 368 plants to assess the morphological differences among the members of the complex and to determine their appropriate taxonomic ranks. The numbers of a priori groups tested were based on taxa recognized in floristic literature, examination of type specimens and 3214 herbarium specimens, and observations of plants in the field and greenhouse. Analyses were performed to determine statistical support for eight a priori species level groups: Solidago albopilosa E.L. Braun, Solidago caesia  L., Solidago curtisii Torr. & A. Gray, Solidago flexicaulis L., Solidago glomerata Michx., Solidago lancifolia (Torr. & A. Gray) Chapm., Solidago macrophylla  Pursh, and Solidago ouachitensis C.E.S Taylor & R.J. Taylor. Additional analyses were preformed to determine statistical support for varietal level a priori groups within S. caesia and S. curtisii. Statistical support for recognizing all 10 a priori groups varied, although in all analyses, the P values were always well below α of 0.05. Based on the results of the discriminant analyses, the following taxa are recognized: S. albopilosa, S. caesia var. caesia , S. caesia var. zedia , S. curtisii var. curtisii , S. curtisii var. flaccidifolia , S. flexicaulis, S. glomerata, S. lancifolia, S. macrophylla, and S. ouachitensis.