Common Names: Round-leaved sundew or Common sundew
Part Used: The flowering plant dried in the air, not artificially.
Habitat: Drosera rotundifolia is found in all of northern Europe, much of Siberia, large parts of northern North America, Korea, Japan and is also found on New Guinea. It grows in muddy edges of ponds, bogs and rivers, where the soil is peaty.
Drosera rotundifolia 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…..CLICK & SEE THE PICTURES
The plant feeds on insects, which are attracted to its bright red colour and its glistening drops of mucilage, loaded with a sugary substance, covering its leaves. It has evolved this carnivorous behaviour in response to its habitat, which is usually poor in nutrients or is so acidic, nutrient availability is severely decreased. The plant uses enzymes to dissolve the insects – which become stuck to the glandular tentacles – and extract ammonia (from proteins) and other nutrients from their bodies. The ammonia replaces the nitrogen that other plants absorb from the soil.
Prefers a sandy peaty soil, succeeding in poor soils and bogs. Requires a sunny position. An insectivorous plant, it can survive in nitrogen poor soils because it gets the nutrients it needs from insects. The upper surfaces of leaves are covered with hairs that secrete a sweet sticky substance.This attracts insects, which become smeared with it and unable to escape – the plant then exudes a digestive fluid that enables it to absorb most of the insect into its system.
Seed – best sown thinly as soon as it is ripe into pots of a free-draining soil with some charcoal added and with a layer of finely chopped sphagnum moss on top. Surface sow and keep the compost moist. The seed usually germinates in 1 – 2 months at 20°c. Grow the plants on in the pots for their first growing season, making sure that the soil does not become dry. Divide the plants in the autumn, grow them on in the greenhouse for the winter and plant them out into their permanent positions in late spring.
Edible Uses: The juice of the plant is used to curdle plant milks. You heat the milk and the leaves together in order to make the milk curdle
Constituents: The juice is bitter, acrid, caustic, odourless, yielding not more than 30 per cent ash, and contains citric and malic acids.
Drosera rotundifolia plant extracts show great efficacy as an anti-inflammatory and antispasmodic, more so than Drosera madagascariensis, as a result of the flavonoids such as hyperoside, quercetin and isoquercetin, but not the naphthoquinones present in the extracts. The flavonoids are thought to affect the M3 muscarinic receptors in smooth muscle, causing the antispasmodic effects. Ellagic acid in D. rotundifolia extracts has also been shown to have antiangiogenic effects.
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.
The sundew has a long history of herbal use, having been popular for its fortifying and aphrodisiac effects. It relaxes the muscles of the respiratory tract, easing breathing and relieving wheezing and so is of great value in the treatment of various chest complaints. The plant has become quite rare and so it should not be harvested from the wild. The flowering plant is antibacterial, antibiotic, antispasmodic, antitussive, demulcent, expectorant and hypoglycaemic. The plant is used with advantage in the treatment of whooping cough, exerting a peculiar action on the respiratory organs. It is also used in the treatment of incipient phthisis, chronic bronchitis and asthma. Externally, it has been used to treat corns, warts and bunions.The plant is harvested in the summer and can be dried for later use. Use with caution. Internal use of this herb causes a harmless colouring of the urine. An extract of the plant contains plumbagin, which is antibiotic against a wide range of pathogens. Because of their protein digesting enzymes, the leaf juice has been used in the treatment of warts and corns. The entire fresh plant, harvested when it is starting to flower, is used to make a homeopathic remedy. It is used mainly in the treatment of coughs and is specific for whooping cough.
Substances in the plant are used to curb the growth of bacteria