1. Conium maculatum Linnaeus, Sp. Pl. 1: 243. 1753.
毒参 du shen
Plants 80–200(–300) cm, essentially glabrous. Basal leaves on long-petioles, petioles 7–25 cm, sheaths small, narrow; blades 2–3-pinnate, 10–30 × 6–28 cm, finely divided; pinnae petiolulate; ultimate segments oblong or ovate-lanceolate, 1–3 × 0.5–1 cm, short-petiolulate, incised or pinnatifid. Leaves gradually reduced upwards. Umbels 4–7 cm across, lateral umbels overtopping the terminal; peduncles 2–7 cm; bracts 4–6, ovate-lanceolate, acuminate, 2–5 mm, reflexed; rays 10–20, 1.5–4 cm, unequal; bracteoles 5–6, ovate, 1.5–3 mm, fused at base; pedicels 10–20, 1–5 mm, unequal. Petals ca. 1.5 × 1 mm. Fruit 2–4 × 1.5–2.5 mm. Fl. and fr. May–Aug. n = 11.
Forest margins, cultivated field margins. Xinjiang [native to the Mediterranean region, widely naturalized in the N temperate zone].
This notorious plant (hemlock) was famously used to kill Socrates. All part of the plants are poisonous (containing toxic alkaloids, C8H17N), but can be used medicinally to relieve pain and reputedly as a cancer cure.