Final answer:
The earliest flowering bulbs are called monocotyledons, which include grasses, lilies, irises, and crocuses. Monocotyledons have a single leaf and their stems do not thicken as the plant matures.
Step-by-step explanation:
The earliest flowering bulbs are called monocotyledons. These plants include grasses, lilies, irises, and crocuses. Monocotyledonous seedlings have a single leaf and their stems do not thicken as the plant matures. On the other hand, dicotyledons, another group of flowering plants, have two leaves and their stems become thicker as the plant matures.