Olive

OLIVE (Olea europaea), the plant that yields the olive oil of commerce, belonging to a section of the family Oleaceae, of which it has been taken as the type. The genus Olea includes about 35 species, very widely scattered, chiefly over the Old World, from the Mediterranean basin to South Africa and New Zealand. The wild olive is a small tree or bush of rather straggling growth, with thorny branches and opposite oblong pointed leaves, dark greyish green above and, in the young state, hoary beneath with whitish scales ; the small white flowers, with four-cleft calyx and corolla, two stamens and bifid stigma, are borne on the last year's wood, in racemes springing from the axils of the leaves ; the drupaceous fruit is small in the wild plant, and the fleshy pericarp, which gives the cultivated olive its economic value, is hard and comparatively thin. In the cultivated forms (0. europaea var. sativa.) the tree acquires a more compact habit, the branches lose their spinous character, while the young shoots become more or less angular; the leaves are always hoary on the under-side, and are generally lanceolate in shape. The fruit is usually oval or nearly globular, in some sorts it is egg-shaped, in others much elongated ; while the dark hue that it commonly assumes when ripe is exchanged in many varieties for violet, green or almost white. At present the wild olive is found in most countries around the Mediterranean, extending its range on the west to Portugal, and eastward to the vicinity of the Caspian, while, locally, it occurs even in Afghan istan. An undoubted native of Syria and the maritime parts of Asia Minor, its abundance in Greece, and the frequent allusions to it by the earliest poets, seem to indicate that it was there also indigenous. It shows a marked preference for calcareous soils and the proximity of the sea.

The varieties of olive known to the modern cultivator are extremely numerous—according to some authorities equalling or exceeding in number those of the vine. In France and Italy at least 3o kinds have been enumerated, but comparatively few are grown to any large extent. The olive tree, even when free increase is unchecked by pruning, is of very slow growth ; but, where allowed for ages its natural development, the trunk sometimes at tains a considerable diameter. De Candolle records one exceeding 23 ft. in girth, its age being estimated at 700 years. The tree in cultivation rarely exceeds 3o ft. in height, and in France and Italy is generally kept much smaller by frequent pruning. The

wood, of a yellow or light greenish-brown hue, is often finely veined with a darker tint, and, being very hard and close grained, is valued by the cabinetmaker and turner.

Propagation and Cultivation.

The olive is propagated in various ways, but cuttings or layers are generally preferred; the tree roots in favourable soil almost as easily as the willow, and throws up suckers from the stump when cut down. Branches of various thickness are cut into lengths of several feet each, and, planted rather deeply in manured ground, soon vegetate; shorter pieces are sometimes laid horizontally in shallow trenches, when, covered with a few inches of soil, they rapidly throw up sucker like shoots. In Greece and the islands grafting the cultivated tree on the wild form is com mon. In Italy embryonic buds, which form small swellings on the stems, are carefully ex cised and planted beneath the surface, where they grow read ily, these "uovoli" soon form ing a vigorous shoot. Occasion ally the larger boughs are in arched, and young trees thus soon obtained ; the olive is also sometimes raised from seed.

Where carefully cultivated, the olive is planted in rows at regu lar intervals, the distance be tween the trees varying in differ ent "olivettes," according to the variety grown. Careful prun ing is practised, the object being to preserve the flower-bearing shoots of the preceding year, while keeping the head of the tree low, so as to allow the easy gathering of the fruit ; a dome or rounded form is generally the aim of the pruner. The fruit when ripe is preferably picked by hand and deposited in cloths or baskets for conveyance to the mill where the oil is expressed; but in many parts of Spain and Greece, and generally in Asia, the olives are beaten down by poles or by shaking the boughs, or even allowed to drop naturally, often lying on the ground until the convenience of the owner admits of their removal; much of the inferior oil owes its bad quality to the carelessness of the proprietor of the trees. The amount of oil contained in the fruit differs much in the various sorts ; the peri carp usually yields from 6o to 7o%. A calcareous soil, however dry or poor, seems best adapted to its healthy development, though the tree will grow in any light soil, and even on clay if well drained ; but, as remarked by Pliny, the plant is more liable to disease on rich soils, and the oil is inferior to the produce of the poorer and more rocky ground the species naturally affects.