Origin of the bifurcating style in Asteraceae

One of the most remarkable reproductive structures of the members of the plant family Asteraceae is the style. Katinas et al. examine the morphology and distribution of lipophilic compounds of the styles in the early branching lineages of Asteraceae and its sister families Goodeniaceae and Calyceraceae.

Their results are put in a phylogenetic framework to discuss the relevance of style features in the evolution of these families. They conclude that vein branching reduction, connation and elongation, and papillae redistribution were steps leading to the bilobation and bifaciality of the Asteraceae styles, keystone changes for the family’s evolutionary success.