Re: how do the number of flower parts and cotyledons differ in monocots&diocots

Dear Casity,

Monocots have 3-parted flowers, while dicots have 4- or 5-parted flowers. Sometimes flowers will their parts in multiples of these numbers; for example, lilies (a group of monocots) have six petals. You can find some more examples at the excellent naturalist website Backyard Nature. Another good reference can be found here.

Monocots have one single cotyledon, while dicots have two (or occasionally multiple) cotyledons. This is where the names of the groups come from: "mono" means "one" in Greek, and "di" means "two." Cotyledon, of course, refers to the first leaf to emerge from the seed. (Many scientific terms have their origins in Greek or Latin. Learning a few basic word roots from these ancient languages can make the thicket of scientific terminology much easier to navigate!)

Grouping flowering plants into monocots and dicots makes it easier to remember the characteristics of the two groups, but recently, scientists have found that the relationship between them is not as simple as we used to think. A good overview of the evolutionary relationships between monocots and dicots can be found here.