Source, Etc

The common bryony, Bryonia dioica, Jaequin (N.O. Cucurbitaceoe) is a climbing and trailing plant, with rough, hairy leaves, common in hedges and thickets in southern England. It must not be confounded with black bryony (Tamus communis, Linne), a very different plant with entire shining leaves. The root is collected in the autumn and used in the fresh state.

Description

The plant produces in the spring aerial stems attaining a great length and arising from a large, tuberous rhizome which is continuous with a thick, fleshy root. This subterranean part of the plant is often of very considerable size and weight, measuring occasionally at the upper extremity 15 cm. or more in diameter, and reaching a length of half a metre, the whole weighing several kilograms. It tapers more or less gradually towards the tip, and is usually simple. When fresh it is of a greyish yellow colour externally, and marked at close intervals with prominent transverse corky ridges often extending half round the root. Internally the root is whitish and fleshy, exuding when cut a juice that is milky from the presence of numerous, minute starch grains. The transverse section exhibits a fine line separating a narrow bark from a large, fleshy wood; the latter contains, more or less uniformly distributed over it, small groups of vessels, radially arranged and extending from the centre to the bark.

The fresh root has an unpleasant odour and a nauseously bitter and acrid taste.

It is sometimes cut into transverse slices and dried; the slices average about 5 cm. in diameter and have a thin yellowish grey cork, a whitish wood marked with concentric rings and radially arranged vessels; they somewhat resemble calumba, but may be distinguished by their yellowish grey cork and whitish wood. The student should observe

(a) The large size and gradually tapering shape,

(b) The transverse corky ridges,

(c) The nauseously bitter taste; and should compare small specimens with horseradish root, which is cylindrical and smooth, and has a pungent taste.

Constituents

An intensely bitter amorphous alkaloid and a dark brown resin, both of which are purgative; an alcohol, bryonol, and various fatty acids. The autumnal root contains, further, large quantities of starch, the grains of which are exceedingly small and impart a milky appearance to the juice that exudes from a freshly cut surface.

Uses

The root when taken internally in full doses acts as a cathartic and diuretic; applied to the skin it is irritant and may cause vesication. It has been recommended for pleurisy, whooping cough, and bronchitis, and has been given in cases of dropsy.

Varieties

Bryonia alba, Linne, a Continental species, is distinguished by its monoecious flowers and black berries, the common bryony having dioecious flowers and scarlet berries. It produces a similar root containing probably the same constituents.