This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The coltsfoot, Tussilago Farfara, Linne (N.O. Compositoe), is a small herb with perennial creeping rhizome, abundant in Great Britain. The leaves appear much later than the flowering stems, and these two parts of the plant are therefore collected separately and usually sold separately. They have been long used as a domestic remedy for coughs.
The flowering stems, which appear in the early spring, are about 15 cm. high, and bear numerous small, narrow, alternate, reddish bracts; they are simple and hairy, many of the hairs terminating in dark, reddish brown glands. The flowerheads are terminal and solitary and surrounded by reddish involucral bracts; they possess numerous ray-florets with short, very narrow, bright yellow ligulate corollas, the disc-florets being less numerous and tubular. The receptacle is flat and naked, the fruits cylindrical, tapering towards the base and provided with an abundant pappus of white simple hairs. The leaves appear much later than the flowers, and arise from separate shoots. They are radical and provided with long stalks; the lamina is cordate about 10 or 15 cm. in breadth, but occasionally much larger. The margin is sinuate-dentate, each tooth terminating in a hard brown point. The upper surface is dull greyish green and minutely wrinkled. Both surfaces are covered when young with loose, white, felted, woolly hairs, but those on the upper surface fall off as the leaf expands. After the leaves have died down the shoot rests, and produces in the following spring a flowering stem, whilst other shoots develop leaves.
Neither leaves nor flowers have, when dried, any characteristic odour or taste. The student should observe
(a) The short, very narrow, ligulate corolla,
(b) The cylindrical fruit with pappus of white, simple bristles,
(c) The shape and margin of leaves and their hairy under surface,
(d) The characteristic glandular hairs on the peduncle.
No active constituent is known. The drug contains a little tannin, and Bondurant (1887) found indications of a bitter glucoside which was not isolated.
Coltsfoot is used as a domestic remedy for coughs.
Fig. 106. - Coltsfoot leaf. About two-thirds natural size.