What is a Monocot or a Dicot, and why do I even need to know?
It’s all to do with how a plant is constructed, and the name comes from how many leaves a seedling has when it first germinates.
Take Grass for instance. When it starts to emerge it has a single long leaf. These first leaves are known as its ‘seed leaves’, or Cotyledons. Any plant that reproduces itself by seed is therefore a Cotyledonous Plant.
And so any plant which only has one seed leaf is known as a Monocotyledonous plant, ‘mono’ meaning one. They are by and large herbaceous, which is to say they do not have woody stems in the sense of timber-like structures. The Banana tree is a giant herb, and its trunk is made up of curled up leaves and leaf stalks with no ‘wood’ in it at all.
Excluding Conifers, everything else is Dicotyledonous, ‘Di’ meaning two. As can be seen in the photo, there are clearly two leaves at the top of the newly emerged shoot.