ANGIOSPERMS: Monocot versus Dicots Biology 112 Monocots & Dicots • Botanists are able to divide the 235,000 species of angiosperms into two large groups based on the structure of their seeds • Inside the seeds of angiosperms are tiny embryonic leaves called cotyledons. The seeds of one group of angiosperms have one cotyledon, called monocotyledons or monocots. • Other angiosperms have two cotyledons. These are called dicotyledons or dicots Cotyledon (seed leaf) Monocots versus Dicots One cotyledon (seed leaf) Two cotyledons (seed leaves) The veins of monocot leaves are parallel to each other The leaves of dicots usually have netlike veins Leaves Monocot versus Dicots Base of a Monocot Leaf: Note the Sheath which connects the Blade to the Stem Typical Dicot Leaf with Reticulate (Net) Venation Monocot Examples • Tulips, daffodils, irises, lilies, palm trees • Do you see veins that are parallel? Dicot Examples • Buttercups, peas, roses, sunflowers, maple trees, and dandelions • Do you see the netlike veins? Which is which? A is _____________ B is __________ Stems Monocot versus Dicot Cross Section of Corn which is a typical Monocot Cross Section of a typical Dicot Stem Root System Dicot versus Monocots Dicot Monocot Floral Parts Monocots Monocots versus Dicots Dicots