Dark opal basil is a cultivar of Ocimum basilicum (sweet basil), developed by John Scarchuk and Joseph Lent at the University of Connecticut in the 1950s. With deep purple, sometimes mottled leaves, it is grown as much for its decorative appeal as for its culinary value.
Basil or sweet basil is a popular culinary herb botanically known as Ocimum basilicum of the family Lamiaceae (mint). Basil is an annual plant, which is originally from Asia before spreading to other parts of the world. Basil is a Greek word βασιλεύς (basileus), which literally means king.