Agenda. Angiosperm- two classes Monocots DicotsDifferences between monocots and dicotsIdentify plants and place them in the two groups. What are they?. Angiosperm - Flowering plants. First appearing at least 110 million years ago from an unknown gymnosperm ancestor, flowering plants have risen to dominance in most of the world\'s floras. Angiosperms are divided in to two groups: monocot and dicot..