Woolly foxglove

Woolly foxglove

Woolly foxglove

Specification & Spread

Woolly foxglove leaves — folia digitalis lanatae
Woolly foxglove — digitalis lanata ehrh.
Figwort family — scrophulariaceae.

It is a perennial herbaceous plant 100-200 cm tall.
The bottom sand leaves are oblong-lanceolate, usually acuminate, entire, 6–12 cm long, 1.5–3.5 cm wide.
The stem leaves are lanceolate and smaller size.
The inflorescence is a long, rather thick pyramidal truss. The axis of the inflorescence, calyx lobes and white-pubescent hairy bracts.
The flowers are brown-yellow, with a spherical, swollen corolla with a protruding long lower dorsal lip, 20-30 mm long and on glandular pedicels.
The fruit is a conical blunt seed box 8-12 mm long.

It blooms in June – August, the seeds ripen in July – September.

Distinctive features of various types of foxglove:

Purple foxglove — Digitalis purpurea L. It is a biennial herbaceous plant. It is cultivated in the North Caucasus, Crimea and Ukraine. In the first year, only a rosette of large, elliptical leaves with a long winged petiole and crenate edge is formed. In the second year, the stems with sessile leaves and flowers appear. The flower corona is purple, inside is white with purple spots. The inflorescence is one-sided multiflorant truss.

Yellow foxglove — Digitalis grandiflora Mill. It is a perennial herbaceous plant. It is found in the wildlife in the Caucasus, the Urals, in the Carpathians on forest lawns. The leaves are oblong-lanceolate, with a sharp tip, serrate edge, with a noticeable median vein and lateral veins of the second order, with yellow flowers. The inflorescence is one-sided multiflorant truss.

Woolly foxglove — Digitalis lanata Ehrh. It is a perennial or biennial herbaceous plant. It is cultivated in the North Caucasus, Ukraine and in Moldova. The leaves are lanceolate, entire, bare and dark green on both sides. The corolla is brown-yellow with lilac veins and globularly swollen. The middle lobe of the lower dorsal lip is spatulate and strongly protrudes. The inflorescence is a pyramidal multicoloured truss.

Spreading and habitat. It grows in South-Eastern Europe in the Balkan Peninsula and in the Danube countries. It can be rarely found in Transcarpathia and Moldova. For medical purposes. It is cultivated in the North Caucasus, Ukraine and Moldova.


All parts of the plant contain cardiac glycosides. The largest number of it is noted in rosette leaves of the first year of plant life.
By now about 30 compounds belonging to cardiac (cardiotonic) glycosides have been isolated and studied from the woolly foxglove.
According to their pharmacological action, the most valuable of it are digilanides (lanatosides) A, B, C, which differ from purpureaglycosides of purple foxglove in the presence of an acetyl group in the third digitoxose molecule, and their secondary glycosides – digitoxin, gitoxin, digoxin.
In addition, steroid saponins – digitonin and tigonin – are found in the plant.

A specific cardiotonic glycoside of woolly foxglove is digilanide (lanatozid) C. Its aglycone is digoxigenin (12-oxydihydroxigenin). During digrolanide C hydrolysis, secondary glycosides are formed – acetyldigoxin and digoxin (digoxigenin with 3 molecules of digitoxose).

Harvesting and storage of raw materials

Harvesting. On the plantations, the rosette leaves of the first year of life are cut off in July-August, and after 1-1.5 months it makes the second, sometimes the third harvesting.
The stem leaves from plants of the second year of life are cut by hand. The raw materials are recommended to be collected in the flowering stage and on a sunny day, as glycosides are accumulated more intensively in the light. While cultivating foxglove as an annual crop, the leaves are cut 2-3 times per summer without petioles (it makes drying difficult, and do not contain biologically active substances).

Security measures. On biennial plantations while harvesting the raw materials, the root system is protected from damage.

Drying. To obtain digilanide C, leaves are dried at a temperature of 80 ºС, and digoxin – not higher than 45 ºС.
Storage. All raw materials must be well packaged. Close  packing promotes better preservation of biologically active substances. Whole raw materials are stored in a dry and dark place. The powder is in ampoules or tightly closed vials.

Whole raw materials
Whole dense, slightly leather-like leaves of lanceolate shape or pieces of leaves. The leaves are entire with clearly visible median and 3-4 lateral veins.
The length is 6-12 (20) cm, the width is 1.5-3.5 cm. The leaf colour plate is green on the top, on the bottom is light green. The veins are yellowish-brown and often reddish-purple at the base of the leaf. The smell is weak. The taste is not determined (poisonous!).

Milled raw material
The pieces of leaves are passed through a sieve with a hole diameter of 7 mm.

Other species.In addition to the mentioned species, ciliate foxglove herb (D. ciliata Trautv.) – Herba Digitalis ciliatae and rusty foxglove leaves (D. ferruginea L., including Shishkin’s foxglove (D. schischkinii Ivanina)) – Folia Digitalis ferrugineae are allowed to use. Both species are endemics of the Caucasus and currently almost never used.

Properties and application

The pharmacological properties of woolly foxglove
Of the cardiac glycosides of woolly foxglove, digoxin is the most studied and digilanid C. The electrochemical mechanism and pharmacological properties of woolly foxglove glycosides are the same as those of purple foxglove.
There are only some features associated with absorption, connection with proteins and excretion from the body.

Application of woolly foxglove

Glycosides of woolly foxglove are used when:

  • acute and chronic circulatory failure II and III stages,
  • tachyarrhythmic form of atrial fibrillation,
  • paroxysmal atrial fibrillation,
  • supraventricular paroxysmal tachycardia.

They are accumulate less, absorb faster and have a stronger diuretic effect than preparations derived from purple foxglove.

  • Infectious diseases,
  • coronary insufficiency,
  • bradycardia, heart disease,
  • myocardial infarction.
  • period of pregnancy and lactation,
  • pediatric use.