Cinchona calisaya aka Ledgerbark

Cinchona calisaya is an evergreen tree in the Rubiaceae family. Its common names include Peruvian bark and quinine. It comes from central Peru through central Bolivia. It grows in cool, damp mountain forests in the Andes. This tropical species occurs at about 1,310–9,840 feet [400–3,000 metres]. People now grow it in many tropical regions for its bark.

It forms a shrub or small tree with woody stems. Garden references give a height and spread of about 20 feet [6 metres]. Some accounts report plants reaching 26 feet [8 metres] tall. It grows at a moderate rate and keeps its leaves year-round. Plants begin to flower after three or four years. The supplied sources give no flower season or detailed fruit traits.

This tree needs moist soil that drains well. It grows in full sun or partial shade. Sandy and loamy soils suit it. Detailed growing notes favour acid soil, with a pH of 5–6. They give a wider tolerated range of 4.5–6.5. Growth is poor or absent on ground exposed to fire. Warm days of 17–24°C suit it best. Temperatures of 5°C or less may kill it. PFAF lists USDA zones 10–12. Its preferred annual rainfall is 2,500–3,000 millimetres. Growers can raise plants from seed or stem cuttings.

The bark has a long history of medicinal use in South America. People used it for fevers and malaria before Europeans learned of it. Heavy wild harvesting followed, before growers set up plantations in Java. The bark contains quinine and quinidine, two active alkaloids. Quinine has an established role in treating malaria. Quinidine affects the heart, so these uses need medical oversight. Commercial growers uproot and harvest trees after eight to twelve years. The sources stress medicinal value rather than garden display.

The inner bark also supplies a bitter flavour for drinks. Extracted quinine flavours tonic water and other fizzy drinks. Powdered bark has been used in tooth powders for its astringent effect. These uses do not make raw bark safe to eat freely. Too much can cause cinchonism, headache, rash, and stomach pain. Serious effects include loss of hearing or sight. Some countries restrict the herb or extracted quinine. The supplied sources name no specific pests or diseases.