Disintegration of the scrophulariaceae

Area of Science:

• Molecular Systematics
• Plant Taxonomy
• Phylogenetics

Background:

• The traditional Scrophulariaceae family (sensu lato) is taxonomically complex and polyphyletic.
• Previous classifications did not accurately reflect the evolutionary relationships within the Lamiales order.

Purpose of the Study:

• To resolve the phylogenetic relationships of genera within Scrophulariaceae (sensu lato) using molecular data.
• To redefine the circumscription of Scrophulariaceae and related families within the Lamiales.

Main Methods:

• DNA sequencing of three plastid genes (rbcL, ndhF, and rps2).
• Phylogenetic analysis of 39 genera from Scrophulariaceae (sensu lato) and related families in Lamiales.

Main Results:

• Identification of at least five distinct monophyletic groups within the analyzed taxa.
• Redefinition of Scrophulariaceae (sensu stricto), Veronicaceae, Orobanchaceae, and Stilbaceae.
• Establishment of the new family Calceolariaceae to accommodate the tribe Calceolarieae.
• The genus Mimulus was found not to belong to any of the five identified major groups.

Conclusions:

• The study provides a robust molecular phylogeny for Scrophulariaceae (sensu lato) and related families.
• The findings necessitate a significant revision of current plant classification systems within the Lamiales.
• The newly erected Calceolariaceae family highlights the deep evolutionary divergence of this lineage within Lamiales.