Oreganos are not in fact considered to be dicots or dicotyledons as they are referred to as by some. Dicots are a group of flowering plants with seeds that generally have two different embryonic leaves which are also known as cortyledons.
The oregano which is also known as Origanum and is a very common species of Orignum in the mint family genus. Oregano is native to the western and southwestern regions of Eurasia and grows best in a warm temperate climate. Although many people mistake organice for a dicot, it is in reality a monocot.