Date of Award

12-1980

Document Type

Thesis

Abstract

The generic name Alloispermum -was proposed by Willdenov in I807 and recently revived by Robinson for several species generally attributed to the genus Galea. The genus Alloispermum by virtue of its pappus, ray flower, leaf and habit features resides in the subtribe Galinsoginae. As presently conceived, the genus comprises 13 species of subshrubs and perennial herbs of montane habitats and ranges from Mexico to northern South America. Seven species occur in Mexico and Central America and six species are indigenous to South America. Two species, A. ovalifolium from Mexico and A. insuetum from Colombia, and one variety, A. colimense var. microcephalum from Mexico are described as new. Two species, A. palmeri and A. tridacoides, have been transferred from the genus Sabazia.

Alloispermum and Sabazia are recognized as weakly separate genera, but because of the lack of appropriate biosystematic studies and the large number of nomenclatural changes needed, the two groups are maintained as distinct.

Alloispermum is characterized by its shrubby or more robust herbaceous habit, capitulescence of several to many heads in corymbose or cymose clusters, and chartaceous to coriaceous phyllaries; whereas, Sabazia consists of smaller perennial and annual herbs with heads either solitary or rarely in cymose clusters, and thinly chartaceous to membranous phyllaries.

DOI

10.31390/gradschool_disstheses.8382

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