Monocotyledons

The flowering plants (Magnoliophyta, angiosperms) can be divided into two groups, Monocotyledons and Dicotyledons.
 
Monocotyledons (John Ray, 1703) are named for the single leaf or cotyledon produced from a sprouting seed. Their lineage probably derives from the first flowering plants. Fossils with characteristics of Monocotyledons occur in deposits from the early Cretaceous period.

Common although not invariable features among Monocotyledons are an irregular distribution of vascular bundles across the stem, leaves with parallel veins, flowers with parts in multiples of three and adventitious roots. Pollen usually has a single furrow running across the grain, and seeds have a single cotyledon. Most plant life styles are found among an estimated 50,000 - 60,000 species, including herbs, epiphytes, vines and trees. Modern molecular analysis has confirmed the coherence of most of the group. However, taxonomy within the Monocotyledons is frequently controversial and changes frequently.
 
The succulent Monocotyledons are an important group of plants and bulbs including the Aloe, Agave, Amaryllis, Pineapple, Dragon's Blood Tree, Bluebell, Orchid and Yam families. The Orchids form the largest Monocotyledon family with over 20,000 species.
 
The mostly non-succulent Grasses must also be mentioned for their important contribution to agriculture and their domination of much of the dry land. There is just one genus of succulent grasses, Dregeochloa, with succulent leaves growing from a pachycaul rhizome.