This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
This interesting plant is found to-day, and not earlier, so far as we know, in the North Temperate and Arctic Zones in Arctic Europe, Siberia, Western Asia, East and West North America, from the Arctic Circle to Florida. In Great Britain it is absent from North Wilts, East Gloucs, W. Gloucs, Cardigan, Carnarvon, Flint, Mid Lancs, Linlithgow, Stirling; and in the Highlands is found at 2300 ft.; but in many counties where it once grew it has disappeared owing to drainage, etc.
Wherever the Sundew is found it is a certain sign of the existence, now or formerly, of a typical bog. It is a plant of the bog or heath, living the life of a Xerophyte, and is associated with such true bog plants as Grass of Parnassus, Cranberry, Rosemary, Bog Pimpernel, Lousewort, Butterwort, Bladderwort, Bog Myrtle, Bog Asphodel, etc. It prefers a shallow pool or wet ground in the middle of some upland bog, where it grows on spongy peat.
The interest attaching to this peculiar plant refers not to its habit of growth so much as to its habit of capturing and assimilating its food, which in this case is organic. It is, in other words, insectivorous, attracting and imprisoning flies in, and by aid of, its glandular sticky leaves (hence the first Latin and English names), which close up when touched, being highly sensitive. The juices secreted1 in the hollow of the leaf are able to digest the flies, just as food is digested by gastric juices in the stomach.
1 The secretion, which is shiny, giving the plant its name, is at the base of the glandular tentacles which enable the plant to capture its prey. Sir Francis Darwin found that plants fed on meat were more vigorous than those kept without animal food. See also Charles Darwin, Insectivorous Plants.
The Sundew is not a tall plant, having long-stalked, rounded leaves (as broad as long, hence the second Latin name), fringed with glands and tentacles. The general shape is spoon-shaped. The racemose flower-stalks, with flowers all turned one way, are more or less erect. The flower-stalk is without leaves. The flowers are small and white, only opening in sunshine. In the autumn stoles with bulbs are put forth.
Photo. J. H. Crabtree - Sundew (Drosera rotundifolia, L.)
This "plant-animal" is about 6 in. high. The flowers bloom in July and August. It is perennial. The flowers are cleistogamic. The stamens are numerous, and united with the petals, which do not fall. The anthers open outwards, and cross-pollination is thereby encouraged. The flowers are in two series. The styles are bent inwards, and the stigmas are club-shaped. The anthers and stigmas ripen together. Insects, usually flies, are attracted to the glandular leaves, and imprisoned and slowly digested, and pollination may be assisted by the miscarriage of such efforts to utilize insect prisoners for food by their being attracted instead to the flowers.
The capsule splitting opposite each loculus allows the seeds to be dispersed to some distance around the parent plant.
Drosera, Cordus, is from drosos, dew, and the second Latin name refers to its rounded leaves.
Sundew is called Lust-wort, Moor-grass, Moor-wort, Red Rot, Rosa Solis, Youth-wort. It is called Red Rot because "Sheepherds do call it the Red Rot because it rotteth sheep".
The name "Rosa Solis" is also the name for a liquor prepared from it. In regard to the name Sundew Lyte says: "This herbe is of a very strange nature and marvellous, for although that the sunne doe shine not, and a long time thereon, yet you shall finde it alwaies moist and bedewed, and the small haires thereof alwaies full of little drops of water, and the hotter the sun shineth upon this herbe, so much the moyster it is, and the more bedewed, and for that cause it was called Rosa solis in Latine, which is to say in English, the dewe of the sun, or sun Dewe".
The Italian liqueur Rossoli is prepared from it in part. It is acrid and caustic, and curdles milk. The Sundew was supposed to remove warts and corns, and to take away freckles and sunburn, presumably in the last case by Doctrine of Signatures! This plant produces a stimulating spirit when distilled with wine. It was once used as a tincture.
Essential Specific Characters: 116. Drosera rotundifolia, L. - Leaves obovate, flat, with red glands, radical, petioles hairy, flowers small, white, on long stalks, seeds chaffy.