Aconitum is a genus of flowering plant belonging to the buttercup family ( Ranunculaceae). There are over 250 species of Aconitum, which are known as aconite, monkshood, or wolfsbane.

These herbaceous perennials are chiefly natives of the mountainous parts of the northern hemisphere, growing in damp soils on mountain meadows. Their darkgreen leaves lack stipules. They are palmate or deeply palmately lobed with 5-7 segments. Each segment again is 3-lobed with coarse sharp teeth. The leaves have a spiral or alternate arrangement. The lower leaves have long petioles.

These are handsome plants, the tall, erect stem being crowned by racemes of large and eye-catching blue, purple, white, yellow or pink zygomorphic flowers with numerous stamens. They are distinguished by having one of the five petaloid sepals (the posterior one), called the galea, in the form of a cylindrical helmet; hence the English name monkshood. There are 2 - 10 petals, in the form of nectaries. The two upper petals are large. They are placed under the hood of the calyx and are supported on long stalks. They have a hollow spur at their apex, containing the nectar. The other petals are small or lack completely. The 3-5 carpels are partially fused at the base.

The fruit is a follicle.

The most common plant in this genus is Aconitum napellus, the Common Monkshood, is a doubtful native of Great Britain, and is of therapeutic and toxicological importance. Its roots have occasionally been mistaken for horseradish. It has a short underground stem, from which dark-colored tapering roots descend. The crown or upper portion of the root gives rise to new plants. When put to the lip, the juice of the aconite root produces a feeling of numbness and tingling. This plant is used as a food plant by some Lepidoptera species including Dot Moth, The Engrailed, Mouse Moth, Wormwood Pug and Yellow-tail.

The roots of Aconitum ferox supply the Indian (Nepal) poison called bikh, bish, or nabee. It contains large quantities of the alkaloid pseudaconitine, which is a deadly poison. Aconitum palmatum yields another of the bikh poisons. The root of Aconitum luridum, of the Himalaya, is said to be as virulent as that of A. ferox or A. napellus.

Many species of Aconitum are cultivated in gardens, some having blue and others yellow flowers. Aconitum lycoctonum, Alpine wolfsbane, is a yellow-flowered species common in the Alps of Switzerland. As garden plants the aconites are very ornamental, hardy perennials. They thrive well in any ordinary garden soil, and will grow beneath the shade of trees. They are easily propagated by divisions of the root or by seeds; care should be taken not to leave pieces of the root where livestock might eat them, owing to the poisonous character.

Aconite has been ascribed with supernatural powers relating to werewolves and other lycanthropes, either to repel them or in some way induce their lycanthropic condition.