The commelinids are a group of 29 interrelated families of flowering plants, named for one of the four included orders, Commelinales.^{[lower-alpha 1]} This subgroup of the monocots accounts for most of the global agricultural output; the grass family alone contains the major cereal grains (including rice, wheat, and maize or corn), along with forage grasses, sugar cane, and bamboo. The palm, banana, ginger, pineapple and sedge families are also commelinids.^[5][6][7]

Traits common to most commelinids include partially fluorescent cell walls, starchy seeds and an extra layer of epidermal wax. Like other monocots, they usually have a single embryonic leaf (cotyledon) in their seeds, scattered vascular systems, leaves with parallel veins, flowers with parts in threes or multiples of three, and roots that can develop in more than one place along the stems.^[8] These plants are found worldwide, even in mainland Antarctica; two species of grass are the only vascular plants found there.^[9]

From the glossary of botanical terms:

• annual: a plant species that completes its life cycle within a single year or growing season
• basal: attached close to the base (of a plant or an evolutionary tree diagram)
• climber: a vine that leans on, twines around or clings to other plants for vertical support
• herbaceous: not woody; usually green and soft in texture
• perennial: not an annual or biennial
• woody: hard and lignified; not herbaceous^[10]

The APG IV system is the fourth in a series of plant taxonomies from the Angiosperm Phylogeny Group.^[2]

• List of plant family names with etymologies