The dried seed of Physostigma venenosum. Western Africa.

Fig. 188. - Calabar Bean, half the natural size.

Characters. - A kidney-shaped bean about an inch long, chocolate-coloured, shining, and with a broad black groove along the whole length of the convex edge. Internally the bean is white, and tastes like an edible bean.

Composition. - Contains two alkaloids - physostigmine or eserine, and calabarine.

Dose. - Of the powdered bean 1 gr. gradually increased.