Class is a taxonomic rank fitting between phylum and order.
Magnoliopsida is a class of flowering plants. Any plant which falls under this class is known as a dicotyledon, also known as dicots. Their seed typically has two embryonic leaves or cotyledons. There are around 199,350 species within this group. Flowering plants that are not dicotyledons are monocotyledons, typically having one embryonic leaf.
↑Hamilton, Alan; Hamilton, Patrick (2006), Plant conservation : an ecosystem approach, London: Earthscan, pp. 2, ISBN 9781844070831