Olea aucheri A.Chev. ex Ehrend.

Olea europaea ssp. africana is a shrub or a small to medium sized tree 5-10 m in height, occasionally reaching 18 m. Bark is grey to brownish-blackish, smooth to rough when old. Leaves narrowly oblong-elliptic, 2-10 cm x 7-17 mm, grey-green to shiny da

In it native range the fruits typically ripen in September, towards the end of the rainy season. Usually only 1 ovule is fertilized.

Acid soils are not a problem for it.

O. europea ssp africana is widely distributed in its native range of southern Africa occurring in a variety of habitats, usually near water, on stream banks, in riverine fringes, but also in open woodland, among rocks and in mountain ravines. It is resistant to both frost and drought. Dry upland evergreen forest (edges, remnants) often associated with Juniperus; may be co dominant; also in woodland on lava flows.

Olive trees have been cultivated for oil extraction and for edible fruit for at least 5 000 years. The deliberate propagation of O. europaea cultivars has long been practised in Mediterranean countries as well as southern Africa, Australia and the New World where olive trees were introduced by Italian and Spanish travellers.

Local attempts in Eritrea to reforest this species have been unsuccessful due to seed germination ranging from 0-5%. A large increase in germination is obtained by removing the endocarp; it imposes a mechanical constraint to germination not a chemical one. Cracking with a hand vice or by rolling a stone over seeds can cause the endocarp to break along or across the suture line, which bisects it. By removing the endocarp germination is greatly enhanced, reaching up to 92% in seed stored for 18 months. Low temperature stratification does not appear to be necessary. Seedlings should not be outplanted shortly after being fertilized. Cuttings root fairly easily. Rooting and the growth of new leaves are strongly influenced by the nutrient status of parent plants and the application of rooting hormone to the base of cuttings.

Unfertilized seedlings show drought tolerance whilst fertilized seedlings do not. Fertilization with adequate watering results in greatly increased shoot growth but little change in root growth. In summary, plants need adequate nutrition and water to grow, and irrigation or fertilizing plants usually increases their growth where water or nutrients are deficient. Fertilization and irrigation need to be carefully managed to ensure optimal growth is consistent with post-transplant survival.

Seed storage behaviour is orthodox. Viability can be maintained for several years in hermetic storage at 3 deg. C with 6-10% mc. The seeds can be stored at dry room temperature for a few years. There are approximately 13 800 seeds/kg.

Reclamation: The high drought tolerance of O. europaea ssp. africana suggests that it is a good candidate for reforestation in semi-arid zones of Africa such as Rora Habab, Eritrea. Ornamental: Olive plantations have the capacity to beautify the landscape.

Food: The main olive products are olive oil and edible olives. The fleshy, oil-bearing mesocarp used in commercial olive growing is absent in the much smaller fruits of O. europaea ssp. africana. Fodder: The plants are much browsed on by livestock. Fuel: In Eritrea the villagers use wild olive extensively to provide fuelwood. Timber: Wood is hard and heavy, weighing approximately 1 140 kg/cubic m. Sapwood is light brown while the heartwood is red-brown to yellow, with dark figuring. The wood is fine-textured and finishes well, and is often used to make ornaments such as wall clocks and vases. Jewellery items such as beads, brooches and bangles are also made from wild olive wood. Although the tree does not produce sawable logs or branches, there are still several furniture-makers that, with great effort produce furniture from the limited quantities of timber. Medicine: The Wandorobo and Kipsigis of Kenya use a root or bark decoction as a remedy for malaria.