Aztec tobacco

An annual herb 0.5–1.5 m tall with stout sticky-hairy stems and few branches. Leaves large, alternate, blades heart-ovate with a rounded to cordate base and pointed tip, glabrous but covered with sticky glandular hairs, strong-smelling, thick and soft. The inflorescence is a terminal panicle; the calyx is a 5-lobed tube and the corolla is a long tube spreading into 5 lobes, pale yellow-green — easily told from the white-pink flowers of common tobacco (N. tabacum); it opens towards evening and is fragrant. The fruit is a globose capsule that opens by valves and sheds very many tiny brown seeds. The whole plant contains nicotine, concentrated mainly in the leaves — up to about 9% of the dry matter of cured leaves, i.e. 3–9 times that of common tobacco (1–3% in N. tabacum).

Nicotiana rustica is native to South America — the Amazon region (Peru, Ecuador, eastern Brazil) — and is considered the ancient tobacco of the Aztecs, used ritually long before N. tabacum became common in North America. Today its leaves are still rolled into mapacho sticks in Amazonian indigenous tradition. In Vietnam, according to historian Đào Duy Anh, the plant came in from Laos (Ai Lao), hence thuốc lào; another account links it to a grower named Hồ Lào (18th century) in Indochina. Thuốc lào is smoked through a water pipe (điếu cày) with a wide bowl, common in the northern midland provinces (Hà Giang, Cao Bằng, Tuyên Quang, Thanh Hóa, Nghệ An); the smoke is far stronger than cigarettes. Because of its very high nicotine, leaves are also soaked and extracted into traditional organic insecticides.