All garden plants can be divided into two kinds. However, when people hear what those kinds are, they tend to ignore the rest of the explanation due to being intimidated by the words. This is particularly true of people who dislike science. The two defining words are scientific terms; monocotyledon and dicotyledon. Don’t be intimidated. It is easy to understand what they are and the difference between the two.
Monocots and dicots
Simply put, monocots have a single cotyledon and dicots have two. Knowing this is isn’t particularly helpful, though, if you don’t know what a cotyledon is.
A cotyledon is a rudimentary leaf that covers or partly covers the embryo in a seed. These give the developing embryo food while the seedling puts out roots and a developing stem.
Dicots are considered to be more advanced plants than monocots, but that has very little meaning to the typical gardener.
Telling the difference
When a dicot germinates or sprouts, a person can normally see two fleshy leaves attached to the seedling. In monocots, there aren’t two fleshy leaves, there is only one. An example of a garden dicot is a bean. An example of a garden monocot is corn. The arrow in the image above is pointing at one of the cotyledons on this bean seedling.
Other differences between monocotyledons and dicotyledons
You might wonder if you can tell the difference between a monocot and a dicot after the plant has grown enough that it is no longer a seedling. The answer is yes.
Look at the leaves. In monocots, the veins of the leaves run the full length of the leaf, from the leaf stem to the tip, parallel to each other. In dicots, the veins branch out. Thus, in a bean plant, the leaf has a network of branched veins. In a corn plant, the veins run to the end of the leaf without branching.
By simply knowing this, you can look at the leaf of a tomato plant, see the branching veins, and correctly conclude that a tomato must be a dicot. You can see the branching veins in the tomato leaf above.
There are other ways to tell the difference, too. Dicots have a main taproot. Monocots have roots that spread out, tending to be shallower and lacking a taproot. How deep the roots are isn’t telling, though. Lettuce is a dicot and has a shallow root structure. However, this also means that you can know that a carrot is a dicot, just from the taproot it has and that we eat.
The individual flowers of dicots also have four or five petals or multiples thereof. The individual flowers of monocots are with petals in multiples of threes.
Knowing all of this, can anyone tell me if onions and chives are monocots or dicots? How about peppermint?