- Botanical: Digitalis purpurea
- Family: Scrophulariaceae
- Hits: 422
Known asRoter Fingerhut, Fingerhut, Fingerkraut, Fuchskraut, Schwulstkraut, Unserer-lieben-Frauen-Handschuh, Waldglöckchen, Waldschelle
Old Usemedical, industry
Parts Usedflowers, leaves
Medicinalcirculation, dropsy, high blood preasure
Heart & Circulationcirculation, dropsy (edema), hemostatic, high blood pressure
Propertiesdiuretic, stimulant, tonic
Digitalis purpurea is an herbaceous biennial or short-lived perennial plant. The leaves are spirally arranged, simple, 10–35 cm long and 5–12 cm broad, and are covered with gray-white pubescent and glandular hairs, imparting a woolly texture. The foliage forms a tight rosette at ground level in the first year. The flowering stem develops in the second year, typically 1 to 2 m tall, sometimes longer. The flowers are arranged in a showy, terminal, elongated cluster, and each flower is tubular and pendent. The flowers are typically purple, but some plants, especially those under cultivation, may be pink, rose, yellow, or white. The inside surface of the flower tube is heavily spotted. The flowering period is early summer, sometimes with additional flower stems developing later in the season. The plant is frequented by bees, which climb right inside the flower tube to gain the nectar within. The fruit is a capsule which splits open at maturity to release the numerous tiny (0.1-0.2 mm) seeds.
Properties & Uses
The foxglove is a widely used herbal medicine with a recognised stimulatory effect upon the heart. It is also used in allopathic medicine in the treatment of heart complaints. It has a profound tonic effect upon a diseased heart, enabling the heart to beat more slowly, powerfully and regularly without requiring more oxygen. At the same time it stimulates the flow of urine which lowers the volume of the blood and lessens the load on the heart. The plant contains cardiac glycosides (including digoxin, digitoxin and lanatosides). Digitoxin rapidly strengthens the heartbeat but is excreted very slowly. Digoxin is therefore preferred as a long-term medication. The leaves are cardiac, diuretic, stimulant and tonic. The leaves should only be harvested from plants in their second year of growth, picked when the flowering spike has grown and about two thirds of the flowers have opened. Harvested at other times, there is less of the medically active alkaloid present. The seed has also been used in the past. The leaves also have a very beneficial effect on the kidneys, they are strongly diuretic and are used with benefit in the treatment of dropsy. Great care should be exercised in the use of this plant, the therapeutic dose is very close to the lethal dose. A homeopathic remedy is made from the leaves. It is used in the treatment of cardiac disorders.
An infusion of the plant prolongs the life of cut flowers. Root crops growing near this plant store better. An apple-green dye is obtained from the flowers
All parts of the plant are highly poisonous. Unsafe for self-medication. Monitoring by a physician to determine correct dose recommended. For overdose give activated charcoal. Can be fatal especially to children
Western Europe, including Britain, from Norway to Spain and Sardinia.
Digitalis contains four important glucosides of which three arecardiac stimulants. The most powerful is Digitoxin, an extremely poisonous and cumulative drug, insoluble in water, Digitalin, which is crystalline and also insoluble in water; Digitalein, amorphous, but readily soluble in water, rendering it, therefore, capable of being administered subcutaneously, in doses so minute as rarely to exceed of a grain; Digitonin, which is a cardiac depressant, containing none of the physiological action peculiar to Digitalis, and is identical with Saponin, the chief constituent of Senega root. Other constituents are volatile oil, fatty matter, starch, gum, sugar, etc. The amount and character of the active constituents vary according to season and soil: 100 parts of dried leaves yield about 1.25 of Digitalin, which is generally found in a larger proportion in the wild than in the cultivated plants. The active constituents of Digitalis are not yet sufficiently explored to render a chemical assay effective in standardizing for therapeutic activity. The different glucosides contained varying from each other in their physiological action, it is impossible to assay the leaves by determining one only of these, such as Digitoxin. No method of determining Digitalin is known. Hence the chemical means of assay fail, and the drug is usually standardized by a physiological test. One of our oldest firms of manufacturing druggists standardizes preparations of this extremely powerful and important drug by testing their action upon frogs.