Botanical name: 

The herb Drosera rotundifolia, Linné (Nat. Ord. Droseraceae). A small plant of the fly-trap family found in boggy situations of Eastern North America and Europe.
Common Names: Sundew, Round-leaved Sundew.

Principal Constituents.—Probably citric acid and a ferment capable of converting albumens into peptones.
Preparation.—Specific Medicine Drosera. Dose, 1/10 to 10 drops.
Specific Indications.—Expulsive or explosive spasmodic cough, with dryness of the air passages; cough of measles; whooping cough; uncontrollable, irritating cough.

Therapy.—Drosera, preferably in small doses, is of great value in the spasmodic dry cough characteristic of measles, and to a lesser extent for that of whooping cough and the irritability of the larynx following the latter. There may be simple irritation, particularly centered in the larynx, or inflammation may be present. It also relieves the tickling sensation in that organ giving rise to spasmodic cough. To a lesser extent it is useful in the coughs of bronchitis, incipient phthisis, spasmodic asthma, and in nervous or sympathetic cough occurring reflexly from other diseases. It probably acts upon the vagus.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.