Cinchona macrocalyx

Cinchona macrocalyx is a tree that grows up to 12 metres (39 ft) high, and around 20 centimetres (7.9 in) wide. The leaf stems are 0.5–2 centimetres (0.20–0.79 in) long. The leaves are papery when dry, elliptic to almost circular in shape, 4–10 centimetres (1.6–3.9 in) long, and 2.8–9.6 centimetres (1.1–3.8 in) wide. The upper surface of the leaves is glossy. The leaves may have domatia. The calyx is 2.8–4.8 millimetres (0.11–0.19 in) long, and has 1.1–3.8 millimetres (0.043–0.150 in) long lobes. The corolla is reddish, 9–13 millimetres (0.35–0.51 in) long, and has 5–9 millimetres (0.20–0.35 in) lobes. The fruit is a dehiscent, more or less ellipsoid to roughly spherical capsule, measuring 10–47 millimetres (0.39–1.85 in) long and 5–12 millimetres (0.20–0.47 in) wide. The endocarp is woody. The seeds are 8–10 millimetres (0.31–0.39 in) long, and 2.9–3.5 millimetres (0.11–0.14 in) wide.

Cinchona macrocalyx is native to the wet tropical biome of Bolivia, Ecuador (Bolívar), and Peru (Cajamarca). It grows in the Andes, at elevations of 2,500–3,000 metres (8,200–9,800 ft).