The two largest classes of flowering plants, the eudicots and monocots together comprise 97 % of the members of this phylum.
The monocots are characterised by one cotyledon (seed leaf) and pollen grains with one pore or slit.
The eudicots have two cotyledons and pollen grains with two pores or slits.
The remaining 3% of flowering plants, the magnoliids, have two cotyledons and pollen grains with one pore or slit; they also have the most primitive features.
