Implications of morphological phylogenetics for the placement of the genera Adenocaulon and Eriachaenium (Asteraceae)

Adenocaulon and Eriachaenium are two problematic genera because their triba l and sub-familial placement in Asteraceae is uncertain. Previous cladistic analyses based on molecular data undertaken to analyze the relationships w ithin Asteraceae, place Adenocaulon in the tribe Mutisieae (Cichorioideae). This paper investigates cladistic relationships among Adenocaulon and Eria chaenium and tribes of subfamilies Cichorioideae and Asteriodeae using morp hological data. Thirty-eight characters were scored across 52 genera select ed as exemplar taxa to represent the current classification system. In the analysis (one tree, length = 86, c.i. = 0.55, r.i. = 0.64) Adenocaulon and Eriachaenium are sister taxa and appear as an isolated clade nested in Cich orioideae. A new, tentative position among the tribes of the paraphyletic C ichorioideae is proposed for these two isolated genera.