Purple basil (ocimum basilicum purpurascens) is a variety of basil with deep, dark purple leaves and pale pink flowers often used as an ornamental plant. When mature, the plant grows to be between two and three feet tall.
Its taste is similar, though less flavorful than sweet basil (ocimum basilicum). The flavor of purple basil is peppery with notes of mint and cloves.
Though edible and highly aromatic, purple basil is not used as often for culinary purposes. Sometimes the leaves and flowers are added to salads to add striking color or the leaves can be infused with vinegar or white wine.
Related to purple basil is opal basil and purple ruffles basil.
Opal basil was created in 1962 and is a hybrid of a beautiful Turkish basil and sweet basil. A mature will be about a foot tall and takes a little bit of knowledge to grow. It won the All-America awards for excellence.
Purple ruffles basil is similar to opal basil, but grows more vigorously and has much larger and jagged leaves. This variety grows to be about two feet tall. It also won the All-America awards for excellence.