Identification

• Monocots have several key traits that set them apart from dicots. In the seed, monocots contain only one cotyledon, or primitive leaf. Dicots contain two. Monocot leaves contain parallel veins, and the vascular tissue in their stems is unorganized. Petals occur in multiples of three, and roots tend to be fibrous. Finally, monocots never form woody tissue.
  
  

History

• The first monocots evolved about 134 million years ago. Although less numerous and in many ways simpler plants than dicots, monocots actually evolved from primitive dicots, plants comparable to the magnolia today.
  
  

Examples

• Some of the most familiar plant families belong to the monocot class. The grasses -- which include crops like corn and wheat -- are monocots. Lilies and orchids represent the monocots among popular ornamental plants. Palms are among the only monocots that grow to the size of trees.