Angiosperm

Angiosperm, member of a large class of seed-bearing plants (the flowering plants), its seeds developing completely enclosed in the tissue of the parent plant (rather than unprotected, as in the only other seed-bearing group, the gymnosperms). Containing about 250,000 species distributed throughout the world, from tiny herbs to huge trees, angiosperms are the dominant land flora. There are 2 subclasses: monocotyledons (with 1 leaf) and dicotyledons (with 2).