Eudicots

The eudicots, Eudicotidae or eudicotyledons are a of s that had been called tricolpates or non- dicots by previous authors. The botanical terms were introduced in 1991 by evolutionary botanist and paleobotanist Carol L. Hotton to emphasize the later evolutionary divergence of tricolpate  from earlier, less specialized, dicots. The close relationships among flowering plants with tricolpate pollen grains was initially seen in morphological studies of. These plants have a distinct trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis. Later evidence confirmed the genetic basis for the evolutionary relationships among flowering plants with tricolpate pollen grains and dicotyledonous traits. The term means "true dicotyledons", as it contains the majority of plants that have been considered dicots and have of the dicots. The term "eudicots" has subsequently been widely adopted in to refer to one of the two largest clades of s (constituting over 70% of the angiosperm species),  being the other. The remaining angiosperms include and what are sometimes referred to as  or paleodicots, but these terms have not been widely or consistently adopted, as they do not refer to a  group.

The other name for the eudicots is tricolpates, a name which refers to the grooved structure of the. Members of the group have tricolpate pollen, or forms derived from it. These pollens have three or more pores set in furrows called colpi. In contrast, most of the other (that is the, the monocots and the paleodicots) produce monosulcate pollen, with a single pore set in a differently oriented groove called the sulcus. The name "tricolpates" is preferred by some botanists to avoid confusion with the dicots, a nonmonophyletic group.

Numerous familiar plants are eudicots, including many common food plants, trees, and ornamentals. Some common and familiar eudicots include members of the such as the common, the ,  and other members of , , , , and. Most leafy trees of midlatitudes also belong to eudicots, with notable exceptions being magnolias and tulip trees which belong to, and , which is not an.

The name "eudicots" (plural) is used in the, of 1998, and , of 2003, for classification of angiosperms. It is applied to a, a monophyletic group, which includes most of the (former) dicots.

"Tricolpate" is a synonym for the "" group, the "true " (which are distinguished from all other flowering plants by their tricolpate  structure). The number of furrows or pores helps classify the s, with  having three  (tricolpate), and other groups having one.

Pollen s are any modification of the wall of the pollen grain. These modifications include thinning, ridges and pores, they serve as an exit for the pollen contents and allow shrinking and swelling of the grain caused by changes in moisture content. The elongated apertures/ furrows in the pollen grain are called colpi (singular colpus), which, along with pores, are a chief criterion for identifying the pollen classes.