Source, Etc

Colchicum corm is the contracted subterranean stem of the meadow saffron, Colchicum autumnale, Linne (N.O. Liliaceae), a plant widely distributed over Europe and abundant in some parts of England in moist meadows and pastures.

The meadow saffron produces in the autumn a conspicuous reddish purple flower springing from the side of a contracted and enlarged stem (corm) situated several inches below the surface of the ground (fig. 100, p. 187). This corm has supplied the flower with the necessary materials for its growth, and has thereby been deprived of part of the reserve material which the leaves that die down in the summer have stored up in it. The proper time for collecting the corm is therefore after the early summer leaves have filled it with reserve material and died down, but before the production of the flower in the autumn has partially exhausted it.

Description

The fresh corms are about 4 cm. long and 3 cm. broad, bluntly conical in shape, flattened on one side, and enveloped in an outer brown and inner reddish yellow membranous coat derived from the leaves of the previous summer. Internally the corm is firm, white, and fleshy; it has a disagreeable odour, and exudes, when cut, a bitter juice that is white and milky from the presence in it of numerous starch grains.

The corms are also cut into thin transverse slices, which are dried at a gentle heat and freed from the remains of the membranes by winnowing. They then form whitish slices about 3 cm. wide, yellowish on their outer surface and reniform in outline, the depression corresponding to the position of the flower. They break readily with a short starchy fracture. The transverse surface exhibits, when smoothed, numerous scattered darker points (fibro-vascular bundles). The drug is inodorous, but has a bitter taste.

The student should observe

(a) The reniform outline of the sliced drug,

(b) The starchy fracture,

(c) The bitter taste.

Constituents

Colchicum corm contains from 0.5 to 0.6 per cent, of the poisonous alkaloid colchicine (compare p. 188). The drug also contains abundance of starch.

Uses

Colchicum is chiefly used to relieve the pain and inflammation and shorten the duration of acute gout and certain gouty affections, but is liable to cause intestinal pain accompanied by vomiting and purging.