This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Veronica: a low, somewhat hairy, trailing plant, with firm leaves set in pairs: from the joints arise slender pedicles, bearing spikes of blue monopetalous flowers, each of which is divided, as is the cup, into four segments, and followed by a flat bicellular capsule, which opens at the upper broad part and sheds small brown seeds.
(a) Horned Clin. Caf. and Exp.
1. Veronica mas five Betonica pauli. Veronica mas supina & vulgatissima C. B. Thea Germanica quibusdam. Veronica officinalis Linn. Male speedwell: with crenated leaves of a roundish oval figure; those on the flowering twigs, long, narrow, and not crenated. It is perennial, and grows wild on sandy grounds and dry commons.
The leaves of veronica have a weak not disagreeable smell, which in drying is dislipated, and which they give over in distillation with water, but without yielding any separable oil. To the taste they are bitterish and roughish: an extract made from them by rectified spirit is moderately bitter and subastringent: the watery extract is weaker, though the quantity of both is nearly the same; whence spirit seems to extract their virtue more completely than water. This herb is of great esteem among the Germans; in disorders of the breast both catarrhous and ulcerous, and for purifying the blood and humours: infusions of the leaves, which are not unpalatable, are drank as tea, and are found to operate sensibly by urine.
2. Teucrium Act. med. berolinens. Chamae-drys spuria major angustifolia C. B. Veronica Teucrium Linn. Mountain speedwell: with sharply serrated leaves of a long oval figure; the lower embracing the stalk by a broad basis. It is a native of Germany.
The leaves and flowers of this species have been greatly commended for dietetic infusions; and said to promote perspiration and urine, to be in general salubrious, and medicinal in seve-ral disorders (a). Cartheuser observes, that they impart to boiling water a greenish colour, a pleasant balsamic smell, and a much more agreeable taste than the preceding veronica. Among us they have not yet been introduced, nor is the plant common: what has usually been called teucrium is a plant of another genus, a large species of germander.