Buffon remarked that the same temperature might have been expected, all other circumstances being equal, to produce the same beings in different parts of the globe, both in the animal and vegetable kingdoms. Yet lawns in the United States are destitute of the common English daisy, the wild hyacinth of the woods of the United Kingdom is absent from Germany, and the foxglove from Switzerland.
Gerarde, in his Herbal (1597), advocates the use of foxglove for a variety of complaints; and John Parkinson, in the Theatrum Botanicum, or Theater of Plants (1640), and later W.
Withering, who, in his Account of the Foxglove (1785), gave details of upwards of zoo cases chiefly dropsical, in which it was used.
Thus, in Veronica, the rotate corolla has one division much smaller than the rest, and in foxglove (Digitalis) there is a slightly irregular companulate corolla.
- Corolla of foxglove (Digitalis purpurea), cut in order to show the didynamous stamens (two long and two short) which are attached to it.
Digitalis purpurea (Foxglove): hardy, 3 to 5 ft., rosy-purple or' white; beautifully spotted; the variety called gloxinioides has regular, erect flowers.
Purpurea, or foxglove, 3 to 5 ft., with its dense racemes of purple flowers, spotted inside, is very showy, but is surpassed by the garden varieties that have been raised.
The leaves of the foxglove, gathered from wild plants when about two-thirds of their flowers are expanded, deprived usually of the petiole and the thicker part of the midrib, and dried, constitute the drug digitalis or digitalis folia of the Pharmacopoeia.
They are occasionally adulterated with the leaves of Inula Conyza, ploughman's spikenard, which may be distinguished by their greater roughness, their less divided margins, and their odour when rubbed; also with the leaves of Symphytum officinale, comfrey, and of Verbascum Thapsus, great mullein, which unlike those of the foxglove have woolly upper and under surfaces.
- This group-name has been given to a large number of substances which have an action similar to that of the foxglove leaves, including the active principles of strophanthus, squill, Urechites suberecta, Convallaria majalis, Nerium Oleander, Helleborus niger, Antiaris toxicaria (the upas tree), and several others.
The earliest known descriptions of the foxglove are those given by Leonhard Fuchs and Tragus about the middle of the 16th century, but its virtues were doubtless known to herbalists at a much remoter period.