The common foxglove (Digitalis purpurea) is a flowering plant that grows throughout western Europe and has been exported to many other countries for both its beauty and its medicinal benefits. There are other members of the digitalis species, many having been bred artificially for their colour and size.
Foxgloves are poisonous, high doses can be fatal. Lesser doses can induce vomiting, headache, an irregular heartbeat and convulsions.
The foxglove is a biennial or perennial plant with a flowering spike that can reach up to two metres. The flowers are bell shaped, purple-pink in colour with spots on the lower lip of the bell. The size of the flowers is just right to fit the tip of a human finger, explaining its Latin name, digitalis, and German name, Fingerhut (thimble.) From experience I have learnt that before inserting a digit into the flower it is prudent to check that it is unoccupied, bumble bees being particularly fond of the foxglove. The English name, it is thought, comes from 'folksglove', where the folk referred to the fairies and elves thought to live in the shade of the woods where foxgloves thrive. The spots on the flowers are the marks left by the elves as they touched them.
The poisonous quality of foxgloves has been known for centuries and it was recommended for treatment of heart complaints as early as the 17th century. The discovery of the active ingredient, digitalis, in the foxglove was not formalized until 1775 by William Withering. Withering was a Scottish doctor who lived and worked in the Midlands and had a keen interest in botany. A patient of his with heart problems was beyond Withering's cure, who thought the poor chap a definite goner. The patient sought alternative treatment from a local gypsy which proved to be highly effective in curing him. Withering was quite taken by this and set about finding the gypsy and somehow got her to give up the secret of the concoction she had administered. Amongst the many ingredients was foxglove and Withering found that dried, powdered leaves of the plant gave the best results. In 1785 he officially introduced its use and drugs based on the active ingredient are still in common use to control heart rate. The common foxglove, digitalis purpurea, contains digitoxin which isn't widely used any more, but a relative, Digitalis lanata, is farmed to produce digoxin, one of the best drugs to stabilize and strengthen an irregular heartbeat. The plants are left to flower before their long downey covered leaves are harvested, as the leaves are at their most active during blossom.
The introduction of foxgloves into North America has, like in so many other cases, caused problems. The plant has taken a strong hold and being an exotic it excludes native species. It is now actively encouraged in the parks of the US to rip the plant up by its roots in order to keep it from completely driving out the native species.
The foxglove is a valuable addition to most gardens, its affinity with shade, its height and showy flowers make it perfect for brightening up dark corners or adding height at the back of a bed. There are variants that will flower in their first year, but these will not always survive for more than one growing season.
http://www.botanical.com
http://www.hort.purdue.edu/newcrop/med-aro/factsheets/FOXGLOVE.html
http://www.ag.usask.ca/cofa/departments/hort/hortinfo/yards/foxglove.html
http://www.bris.ac.uk/Depts/Chemistry/MOTM/digitalis/digtalis.htm
http://www.nps.gov/redw/foxglove.htm