Digitalis ( /ˌdɪdʒɨˈteɪlɨs/[2] or /ˌdɪdʒɨˈtælɨs/[3]) is a genus of about 20 species of herbaceousperennials, shrubs, and biennials that are commonly called foxgloves. This genus is native to western and south western Europe,[4] western and central Asia, and northwestern Africa. The flowers are produced on a tall spike, are tubular, and vary in colour with species, from purple to pink, white, and yellow. This is a biennial plant which is often grown as anornamental plant due to its vivid flowers. These range in colour from various purple tints through various shades of light gray, and to purely white. The flowers can also possess various marks and spottings. The first year of growth of the Common Foxglove produces only the stem with its long, basal leaves. During the second year of the plant's life, a long leafy stem from 50 to 255 centimeters tall grows atop the roots of healthy plants.[5] [6] The term digitalis is also used for drug preparations that contain cardiac glycosides, particularly one called digoxin, that are extracted from various plants of this genus.

Medicinal use and mechanism of action

A group of medicines extracted from foxglove plants are called Digitalin. It is used to increase cardiac contractility (it is a positive inotrope) and as anantiarrhythmic agent to control the heart rate, particularly in the irregular (and often fast) atrial fibrillation.  Digitalis is hence often prescribed for patients in atrial fibrillation, especially if they have been diagnosed with congestive heart failure.  It was also approved for the control of ventricular response rate for patients with atrial fibrillation. Recent American College of Cardiology/American Heart Association guidelines recommend digoxin for symptomatic chronic heart failure for patients with reduced systolic function, preservation of systolic function, and/or rate control for atrial fibrillation with a rapid ventricular response. Digoxin has not been promoted by the pharmaceutical industry and has received little attention at national and international meetings, possibly the result of the development and promotion of other, newly patented therapies for heart failure. Also, safety concerns about digoxin therapy–increased mortality in women also may have contributed to this decrease in its use.

A group of pharmacologically active compounds are extracted mostly from the leaves of the second year's growth, and in pure form are referred to by common chemical names such as digitoxin or digoxin, or by brand names such as Crystodigin and Lanoxin, respectively. 

Digitalis toxicity (Digitalis intoxication) results from an overdose of digitalis and causes anorexia, nausea, vomiting and diarrhoea, as well as sometimes resulting in xanthopsia (jaundiced or yellow vision) and the appearance of blurred outlines (halos). Bradycardia also occurs. Because a frequent side effect of digitalis is reduction of appetite, some individuals have used the drug as a weight loss aid.