Holy basil is a plant that has violet flowers and blossoms; the stems are green, but sometimes have a purple tinge. This type of basil is much spicier than the other basil variations. Medicinal preparations are made from the leaves, stems, and seeds of the plant.
Holy basil is used to treat many conditions, including H1N1 (swine) flu, diabetes, the common cold, headache, fever, stress, upset stomach, earache and more. It has also been used as a mosquito repellant and topically (on the skin) to treat ringworm.