Oregano is a common species of Origanum, a genus of the mint family (Lamiaceae). It is native to temperate western and southwestern Eurasia and the Mediterranean region. Oregano is a perennial herb, growing from 20–80 cm (7.9–31.5 in) tall, with opposite leaves 1–4 cm (0.39–1.57 in) long. Oregano will grow in a pH range between 6.0 (mildly acidic) and 9.0 (strongly alkaline), with a preferred range between 6.0 and 8.0. The flowers are purple, 3–4 mm (0.12–0.16 in) long, produced in erect spikes. It is sometimes called wild marjoram, and its close relative O. majorana is known as sweet marjoram.