Coca is a plant in the family Erythroxylaceae, native to north-western South America. The plant plays a significant role in traditional Andean culture. Coca leaves contain cocaine alkaloids, a basis for the drug cocaine, which is a powerful stimulant.

The plant resembles a blackthorn bush, and grows to a height of 2–3 m (7–10 ft). The branches are straight, and the leaves, which have a green tint, are thin, opaque, oval, and taper at the extremities. A marked characteristic of the leaf is an areolated portion bounded by two longitudinal curved lines, one line on each side of the midrib, and more conspicuous on the under face of the leaf.

The flowers are small, and disposed in little clusters on short stalks; the corolla is composed of five yellowish-white petals, the anthers are heart-shaped, and the pistil consists of three carpels united to form a three-chambered ovary. The flowers mature into red berries.

The leaves are sometimes eaten by the larvae of the moth Eloria noyesi.

Species and classification

There are twelve main species and varieties. Two subspecies, Erythroxylum coca var. coca and E. coca var. ipadu, are almost indistinguishable phenotypically; a related high cocaine-bearing species has two subspecies, E. novogranatense var. novogranatense and E. novogranatense var. truxillense that are phenotypically similar, but morphologically distinguishable. Under the older Cronquist system of classifying flowering plants, this was placed in an order Linales; more modern systems place it in the order Malpighiales.

Cultivation

Fresh samples of the dried leaves are uncurled, are of a deep green on the upper, and a grey-green on the lower surface, and have a strong tea-like odor; when chewed they produce a pleasurable numbness in the mouth, and have a pleasant, pungent taste. They are traditionally chewed with lime to increase the release of cocaine from the leaf. Older specimens have a camphoraceous smell and a brownish color, and lack the pungent taste.

The seeds are sown from December to January in small plots (almacigas) sheltered from the sun, and the young plants when at 40–60 cm in height are placed in final planting holes (aspi), or if the ground is level, in furrows (uachos) in carefully weeded soil. The plants thrive best in hot, damp and humid situations, such as the clearings of forests; but the leaves most preferred are obtained in drier localities, on the sides of hills. The leaves are gathered from plants varying in age from one and a half to upwards of forty years, but only the new fresh growth is harvested. They are considered ready for plucking when they break on being bent. The first and most abundant harvest is in March after the rains, the second is at the end of June, and the third in October or November. The green leaves (matu) are spread in thin layers on coarse woollen cloths and dried in the sun; they are then packed in sacks, which must be kept dry in order to preserve the quality of the leaves.