The Oreganum genus contains many perennial herbs and subshrubs that are native to western Asia and the Mediterranean region, though some have naturalized in North America. The most common species are familiar culinary herbs, including Origanum vulgare and Origanum majorana. Oregano leaves are generally oval, dark green, and positioned in opposite pairs along the stems. Some varieties have fuzzy leaves.
Oregano starts as a ground-hugging rosette of leaves, but it can easily grow to about 2 feet tall. It's generally planted in the spring and grows quickly, providing leaves suitable for cooking almost immediately. Note that oregano is toxic to pets, so be mindful of where you plant it.