The genus Scopola is a connecting link between Atropa and Hyoscyamus, its leaf, flower and rhizome resembling the former, and the fruit the latter. The Japanese Scopola japonica is so closely allied that it is doubtful if it can be regarded as a distinct species.

S. Carniolica grows in damp, stony places in hilly districts and resembles belladonna both in appearance and characteristics. It only grows to the height of 1 foot, and has thin leaves, its fruit being a transversely dehiscent capsule.

The rhizome is horizontal, curved, almost cylindrical, and somewhat flattened vertically. It is usually found in pieces from 2 1/2 to 7 1/2 cm. long and 0.8 to 1.6 cm. broad, often split before drying. The upper surface is marked with closely-set, large, cup-shaped stem-scars, and the colour varies from yellowish-brown to dark, brownish-grey; the fracture is short and sharp, showing a yellowish-white bark, its corky layer dark brown, or pale brown, the central pith being rather horny. It has scarcely any odour, and the taste is sweetish at first, but afterwards bitter and strongly acrid. The Japanese rhizome is larger, with circular scars, not whitish when broken, and having a slightly mousy, narcotic odour, and practically no bitterness in taste.

The bark of S. Carniolica is less thick than in belladonna and the starch grains smaller.

Scopolia is but little used in Britain, but has been used in America for many years in the manufacture of belladonna plasters.