Drosera rotundifolia

Herbs gallery - Sundew

Common names

  • Common Sundew
  • Red Rot
  • Sundew

Sundew (botanical name, Drosera rotundifolia) is a carnivorous plant. It is a permanently growing herb that grows up to a height of 8 inches. The plant bears curved, dish-shaped leaves on elongated stalks, which appear in rosette. The leaves are swathed with glandular bristles which exude a gluey sap that draws and traps small insects. The sap encloses a potent digestive juice that converts the protein in the trapped insect into a substance that can be soaked up by the plant via the leaf surface. Sundew bears white/pink blooms during the June-August period, which appear in long clusters at the end of leafless stems.

In the case of the common sundew, the leaves are usually in the formation of a basal rosette. The slender, hairy petioles measuring about 1.3 cm to 5 cm in length, support long laminae that measure about 4 mm to 10 mm. The top surface of the lamina is thickly swathed with reddish glandular bristles that exude gluey mucilage.

The flowers of common sundew appear on one plane of a solitary, slim, bald stalk that originates from the middle of the leaf rosette. The white or pink flowers have five petals and each yields slender and tapered seeds that measure 1 mm to 1.5 mm in length.

During winters, the common sundew makes a hibernaculum with a view to endure the cold climatic conditions. The hibernaculum comprises of a bud that is firmly coiled leaves at the level of the ground.

As soon as any little gullible insect perches on the sundew leaf, it is immediately trapped. There are disc-shaped leaves at the bottom of the insectivorous plant's elongated flower stalks that are covered with bristles that discharge a sticky substance through their tips. When the sun's rays fall on this sap, it glistens and draws insects towards it. As soon as the insect comes in contact with the hair-like bristles, they bend inwards and down on the living thing. At the same time, added amounts of sap, that encloses digestive enzymes, transforms the protein of the insect's body into the plant's food.

Way back in the 13th century, alchemists first noticed the positive effects of using the sap exuded by common sundew in treating tuberculosis or consumption. During the 16th century, noted English herbalist John Gerard noted in his Herball that doctors believed sundew to be an unusual and the only remedy for all types of lung diseases, especially tuberculosis. In the present times, practitioners of herbal medicine suggest the use of sap from the sundew plant to alleviate coughs attributed to irritation and confirm that it possesses antispasmodic attributes which facilitate in stopping coughing.

The plant gets its genus name Drosera from the Greek term denoting 'dew'. The sap of the herb which has resemblance to dew is exuded by its leaves sometime during the noon. It is the same time when the flowers of sundew open up for a brief period in the presence of sunlight.

Parts used

Aerial parts.


The common sundew plant has a number of therapeutic uses. For instance, this herb is highly effective in treating spasmodic chest conditions like asthma, bronchial asthma and whooping cough. Apart from unwinding the respiratory tract muscles, common sundew also facilitates breathing, provides relief from wheezing in addition to reducing spasms caused by whooping cough. Generally, this herb is blended with thyme in syrup and it is a very useful medication for treating coughs in children. In addition, herbalists also prescribe sundew to cure gastric disorders.

Sundew has been used as an herbal medication for long and has been popular owing to its strengthening as well as aphrodisiac properties. As aforementioned, this insectivorous plant is highly effective in treating a variety of chest afflictions. Presently, this herb is rarely found and, hence, it ought not to be collected from the wild. The flowering sundew plant possesses antibiotic, antibacterial, anti-tussive (any medication or substance that suppresses coughing), antispasmodic, demulcent (any substance that causes soothing), hypoglycemic (any substance that lowers blood glucose levels) and expectorant attributes. In addition, the herb is also employed in the treatment of chronic bronchitis and incipient phthisis (initial stages of tuberculosis). Sundew is also applied topically to heal warts, corns and bunions.

The entire sundew plant is harvested during the summer and dried for use when necessary. This herb should always be used cautiously and it needs to be noted that taking this herb internally often results in an undamaging pigmentation of the urine. An extract obtained from sundew plant encloses plumbagin, which works as an antibiotic agent against an assortment of pathogens. As the plant contains enzymes that facilitate digestion of protein, the juice of sundew leaf has been employed in treating corns and warts. The entire sundew plant is harvested in summer when it begins to bloom and is used to prepare a homeopathic medication.

Chemical compounds enclosed by the sundew plant are employed to restrain bacterial growth. Since the leaves of this herb have the aptitude to sour milk, earlier, people in Sweden used them to make cheese. In the ancient times, herbalists were of the view that the 'dew' on the plant's leaves, that remained despite the hottest sun had the qualities of endowing long life as well as youth to people who drank it. In fact, the plant has derived its name from the word 'dew'.

Other medical uses

Habitat and cultivation

Sundew is native to North America, Europe and Asia and is found growing in the wild in swampy ground at a maximum height above sea level of 6,000 feet (1,800 meters). Earlier, sundew was collected when the plant was in full bloom during summer. As sundew is rarely found these days, it is advisable not to collect the plants growing in the wild.

Common sundew has a preference for swampy soil, although it survives in poor soils and quagmires. The plant requires a sunlit position to thrive well. A carnivorous plant, especially trapping insects, sundew has the aptitude to endure soils that are poor in nitrogen content since it receives its nourishments from the insects. The top planes of the leaves of this plant are swathed with bristles that exude a sweet gluey substance. This substance draws the insects, which are daubed with the sticky substance making it difficult for them to escape. Sundew also secretes a digestive fluid that facilitates it to soak maximum parts of the insects into its structure.

Common sundew is generally propagated with its seeds, which need to be sparsely sown into freely draining soil immediately when they are mature. The soil needs to be mixed with some charcoal having a fine layer of sliced sphagnum moss over it. The seeds must be sown close to the surface and the compost should be kept wet. Normally, the seeds of sundew germinate within one to two months when the temperature is maintained at 20°C. During their first growing season, the plants ought to be grown in the pots and you ought to make sure that the soil in the pot does not dry up. In autumn, divide the plants and grow them in the greenhouse for the first winter. The plants may be transplanted in their permanent positions outdoors during the later part of spring.


Sundew contains naphthaquinones, enzymes, flavonoids, and volatile oil. The naphthaquinones are antispasmodic, antimicrobial, and also cough-suppressing.

Usual dosage

Common sundew is used in a number of forms for therapeutic purposes, for instance infusion and tincture.

Infusion: To prepare an infusion with sundew, add a teaspoonful of the dehydrated herb in a cup of steaming water and allow it to infuse for about 10 to 15 minutes. Filter the solution and drink it thrice every day.
Tincture: Sundew tincture should be taken in dosage of 1 ml to 2 ml thrice every day.

Side effects and cautions

When sundew and its formulations are taken according to the prescribed dosage, it is believed to be a safe remedy. However, when taken in excessive amounts or higher doses, the herb may result in gastrointestinal irritation in a number of people. Here is a word of caution. This herb should never be given to pregnant women and nursing mothers.

How it works in the body

Naphthaquinones enclosed by the sundew plant is thought to be responsible for the herb's antispasmodic activities, especially providing relief from coughing convulsions. This particular attribute of the herb has made it very popular in Europe. The naphthaquinones enclosed by this herb comprise ramentone, plumbagin, biramentaceone and ramentaceon. Pharmacological researches undertaken with sundew have clearly shown that the herb has a noticeable antispasmodic activity in the respiratory tract. It was found that one naphthaquinone present in sundew plant in an animal study was analogous to codeine in its competence to restrain the desire to cough. Nevertheless, this finding was not repeated in studies undertaken on humans. Owing to this impact of the herb, it is frequently denoted as an herbal anti-tussive. In studies conducted on humans, this property of the herb was exhibited either individually or in conjugation with added herbs for treating coughs related to laryngitis, pharyngitis, bronchitis as well as whooping cough.

Collection and harvesting

The entire sundew herb is harvested while the herb is in full bloom during July and August.


To treat asthma, sundew may be used in combination with other herbs like pill-bearing spurge and grindelia.


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