Erythroxylum coca

Erythroxylum coca is one of two species of cultivated coca.
Description.
The coca 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.
Unlike "Erythroxylum novogranatense, Erythroxylum coca" requires very acidic soil conditions. Soil acidity and water acidity need to be below pH 5.5, with the optimal value being pH 3.5, similar to that of Rhododendron potting soils. At pH 6.5 and above, chlorosis and leaf distortion occur.
The leaves are sometimes eaten by the larvae of the moth "Eloria noyesi".
Taxonomy.
Among the genus "Erythroxylum", cocaine-rich leaves are obtained from four taxa:
Amazonian coca.
"Erythroxylum coca" var. "ipadu", also known as Amazonian coca, is closely related to "Erythroxylum coca" var. "coca", from which it originated relatively recently. "E. coca" var. "ipadu" does not escape cultivation or survive as a feral or wild plant like "E. coca" var. "coca" It has been suggested that due to a lack of genetic isolation to differentiate it from "E. coca" var. "coca", "E. coca" var. "ipadu" may be better defined as a distinct cultivar than a taxonomic variety.
Unlike the other species of coca which are propagated through seeds, "E. coca" var. "ipadu", which rarely produce seeds, is propagated through stem cuttings which remain viable for several weeks if kept moist.
Since Amazonian coca is vegetatively propagated, entire plantations may be populated from the same clone. "E. coca" var. "ipadu" is specially adapted to the shifting agriculture of semi-nomadic Amazonian peoples. Since cuttings of "E. coca" var. "coca" do not easily root, it is likely that "E. coca" var. "ipadu" has been artificially selected for its ease of vegetative propagation.
In contrast to the Andean "E. coca" var. "coca", Amazonian "E. coca" var. "ipadu" is typically a weaker plant evidenced by the fact that after a few years plants lose their vigor and easily fall prey to disease or insect infestation. Overharvesting can speed up this process.
Amazonian coca is prepared differently than the other three cultivated cocas. After fire-toasting the leaves dry, they are pulverized. Once sifted, the powder is combined with ashes from plants which serve as the necessary alkaline admixture for coca chewing.