digitalis

a genus of plants of the family Scrophulariaceae. Plants of this genus are perennial or biennial grasses; rarely are they subshrubs or shrubs. The alternate, entire leaves are lanceolate or oblong. The yellow, purple, or yellow-brown flowers are irregular and often large; they are generally in dense terminal racemes. The perianth is five-parted; the bilabiate corolla is campanulate, thimble-shaped, or inflated. The fruit is a capsule.

There are approximately 35 species of Digitalis, distributed in Europe, western Asia and northern Africa; the Mediterranean region abounds in Digitalis. Of the six species found in the USSR, four grow only in the Caucasus and two grow in the Caucasus, the European USSR, and Western Siberia. They are found primarily in hardwood and mixed forests and in meadows, thickets, and pastures; they also grow on slopes.

All species of Digitalis are poisonous because they contain glycosides, primarily in their leaves. Some species are valuable medicinal herbs. These species include common foxglove (Digitalis purpurea) and yellow foxglove (D. grandiflora), which grow in the European USSR, the Caucasus, and the southern part of Western Siberia; Grecian foxglove (D. lanata), which grows in the Transcarpathian and Odessa oblasts; and such Caucasian species as rusty foxglove (D. ferruginea), D. Schischkinii, and D. ciliata.

The glycosides in the leaves regulate heart activity, increase urine elimination, and reduce edema. Medicinal preparations in the form of powders, tinctures, extracts, and neogalenic preparations (such as gitalen) are made from dried leaves, as are secondary glycosides (digitoxin, digoxin). Digitalis preparations are used under strict medical supervision for treating heart disease. Some species of Digitalis are ornamentals.

In the USSR, common foxglove is cultivated in Krasnodar Krai and Western Siberia; Grecian foxglove is raised in the Northern Caucasus and the Ukraine. Good yields are obtained on light chernozem soils. Foxglove should be planted on fields that have lain fallow or on which winter crops, annual hay grasses, and well-fertilized industrial and other row crops were previously cultivated. The seeds are generally sown 60 cm apart in the fall or spring; the sowing rate is 6–7 kg of seeds per hectare. Organic and inorganic fertilizers are applied during plowing. In the first and second years, the plants require nitrogen and phosphorous supplements.

Under optimum weather conditions and agricultural methods, the leaves may be gathered two or three times in the first year and one or two times in the second. The leaves of annual crops may be harvested first in July or August and later at intervals of one to 1 ^x/i months. The leaves of biennial foxglove may first be picked between shoot formation and flowering and later during massive flowering.