The close relationships among flowering plants with tricolpate pollen grains was initially seen in morphological studies of shared derived characters.

These plants have a distinct trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis.

[3] Later molecular evidence confirmed the genetic basis for the evolutionary relationships among flowering plants with tricolpate pollen grains and dicotyledonous traits.

One of the genetic traits which defines the eudicots is the duplication of DELLA protein-encoding genes in their most recent common ancestor.

In contrast, most of the other seed plants (that is the gymnosperms, the monocots and the paleodicots) produce monosulcate pollen, with a single pore set in a differently oriented groove called the sulcus.

The number of pollen grain furrows or pores helps classify the flowering plants, with eudicots having three colpi (tricolpate), and other groups having one sulcus.