Saxifragales

Saxifragales is an order of flowering plants. Their closest relatives are a large eudicot group known as the rosids by the definition of rosids given in the APG II classification system. Some authors define the rosids more widely, including Saxifragales as their most basal group. Saxifragales is one of the eight groups that compose the core eudicots. The others are Gunnerales, Dilleniaceae, rosids, Santalales, Berberidopsidales, Caryophyllales, and asterids.

Saxifragales has an extensive fossil record. The extant members are apparently remnants of a formerly diverse and widespread order.

Saxifragales, as it is now understood, is based upon the results of molecular phylogenetic studies of DNA sequences. It is not part of any of the classification systems based on plant morphology. The group is much in need of comparative anatomical study, especially in light of the recent expansion of the family Peridiscaceae to include Medusandra, a genus that before 2009, had usually not been placed in Saxifragales.

The order is divided into suprafamilial groups as shown on the phylogenetic tree below. These groups are informal and are not understood to have any particular taxonomic rank.

Read more about Saxifragales:  Families, History, Phylogeny