SundewBotanical Name: Drosera rotundifolia (LINN.)
Family: N.O. Droseraceae
Synonyms: Dew Plant. Round-leaved Sundew. Red Rot. Herba rosellae. Sonnenthau rosollis. Rosée du Soleil.
Part Used: The flowering plant dried in the air, not artificially.
Habitat: Britain, and in many parts of Europe, India, China, Cape of Good Hope, New Holland, North and South America, Russian Asia.
Description: This little insectivorous plant is found growing in muddy edges of ponds, bogs and rivers, where the soil is peaty. It is a small herbaceous, perennial, aquatic plant, with short and slender fibrous root, from which grow the leaves. These are remarkable for their covering of red glandular hairs, by which they are readily recognized, apart from their flowers which only open in the sunshine. Their leaves are orbicular on long stalks, depressed, Iying flat on ground and have on upper surface long red viscid hairs, each having a small gland at top, containing a fluid, which looks like a dewdrop, hence its name. This secretion is most abundant when the sun is at its height. Flower-stems erect, slender, 2 to 6 inches high, at first coiled inward bearing a simple raceme, which straightens out as flowers expand; these are very small and white, appearing in summer and early autumn. Seeds numerous, spindleshaped in a loose chaffy covering contained in a capsule. These hairs are very sensitive, they curve inward slowly and catch any insects which alight on them; the fluid on the points also retains them. After an insect has been caught, the glandular heads secrete a digestive fluid which dissolves all that can be absorbed from the insect. It has been noted that secretion does not take place when inorganic substances are imprisoned.
Constituents: The juice is bitter, acrid, caustic, odourless, yielding not more than 30 per cent ash, and contains citric and malic acids.
Medicinal Action and Uses: Used with advantage in whooping-cough, exerting a peculiar action on the respiratory organs; useful in incipient phthisis, chronic bronchitis, asthma, etc., the juice is said to take away corns and warts, and may be used to curdle milk. In America it has been advocated as a cure for old age; a vegetable extract is used together with colloidal silicates in cases of arterio sclerosis.
Dosages: 2 fluid drachms of the saturated tincture added to 4 fluid drachms of water or wine and a teaspoonful taken for a dose. Fluid extract, 10 to 20 drops. Solid extract, 2 to 5 grams.