Olea ( ) is a genus of flowering plants in the family Oleaceae. It includes 11 species accepted by Plants of the World Online native to warm temperate and tropical regions of the Middle East, southern Europe, Africa, southern Asia, and Australasia.
For humans, the most important and familiar species is by far the olive (Olea europaea), native to the Mediterranean region, Africa, southwest Asia, and the Himalayas, which is the type species of the genus. The native olive (O. paniculata) is a larger tree, attaining a height of 15–18 m in the forests of Queensland, and yielding a hard and tough timber. The yet harder wood of the black ironwood O. capensis, an inhabitant of Natal, is important in South Africa.
Olea species are used as food plants by the larvae of some Lepidoptera species including double-striped pug.
Species
11 species are currently accepted: They have simple leaves with short petioles, and their flowers are typically bisexual. While they can adapt to many environmental conditions, they thrive in arid climate. Olea leaves have trichomes on the underside, which protect the plants in dry conditions by reducing water loss and provide UV-B protection. The cultivated olive, Olea europaea, was first domesticated in the Levant around 6,000 years ago, and today there are over 2,000 cultivars in the Mediterranean basin alone.
Taxonomy
Historically, Olea was organized into 3 subgenera: Olea, Tetrapilus, and Paniculatae. Subgenus Olea was then split into two sections, Olea and Ligustroides. The olive complex is distributed from China to South Africa, across the Mediterranean basin, and the Canary Islands. However, Tetrapilus was later reclassified as a subgenus of Olea due to insufficient molecular evidence supporting it as a genus.