ing and induce sleep.^142 Though frequent to common over much of the Brit-
ish Isles at least since the time of William Turner, it tends to occupy only late-
created habitats and has the suspect look of a slow-spreading invader from
the Continent. That so conspicuous and easily distinguished a plant scarcely
features as a folk herb in the British Isles, even though long established in
official medicine, adds strength to that suspicion.
Digitalis purpurea Linnaeus
foxglove, fairy fingers, fairy thimble, throatwort, floppy dock;
lus mór(Irish and Scots Gaelic)
western Europe, Morocco; introduced into North America,
Australasia and elsewhere
The story of William Withering’s testing of the therapeutic value of the old
folk herb Digitalis purpurea and its subsequent adoption by official medi-
cine has been recounted many times, particularly in more recent years. Not
only was it a landmark in the gradual reawakening to the possible genuine-
ness of many long-derided country remedies, but Withering’s ten years of
patient experimenting with the plant’s properties and his pioneering devel-
opment of the technique of dose titration have earned him acclaim as the
founder of clinical pharmacology. The story, however, often underplays the
extent to which species of foxglove had already been recommended for var-
ious purposes by earlier writers, including the authors of the most widely
read English herbals (though not of the Classical texts^143 ). Medieval Irish
monks are even known to have valued the plant as a diuretic to cure dropsy,
the particular action which caught Withering’s attention in 1775,^144 when
he was introduced to an old family recipe handed down from that of a Shrop-
shire herb woman and, thanks to his recently acquired expertise as a field
botanist, identified which of the score or so ingredients in that ‘cocktail’ was
producing the effect in question. Withering’s interest was confined strictly
to the plant’s diuretic action and its ability to slow the pulse rate, the latter
which eventually brought it into general use for treating heart failure. It is
now known that about a dozen different glycosides are present in Digitalis
species but that the content of them varies through the year and in different
parts of the plant, the root having the least.
Considering how well known its violent and even fatal action was, it is
surprising that foxglove has been used as extensively as it has been in both the
written and unwritten traditions, and for a considerable range of ailments. In
Scotland the older legal records contain numerous cases of children’s deaths
254 Linaria vulgaris