Stems: slender, glabrous. Leaves: orbicular, spreading on the ground. Flowers: in a one-sided raceme, four to twelve flowered. Fruit: seeds fusiform, pointed at both ends.
This bog-herb has a quantity of small round leaves that grow on flat stalks, and are covered with reddish glandular hairs which secrete a fluid that entraps insects. This fluid is exuded in tiny drops at the tips of the hairs, so that the plant always appears to be covered with dew and is very sticky. The white flowers grow in a one-sided cluster, and open usually in sunshine, but only during a very few hours of the day, sometimes not opening at all for several days in succession. The Sundews grow chiefly in wet places, preferably in sphagnum bogs.
" What's this I hear About the new carnivora? Can little plants Eat bugs and ants And gnats and flies? A sort of retrograding; Surely the fare Of flowers is air, Or sunshine sweet; They shouldn't eat, Or do aught so degrading."
It is perfectly true that the Sundew not only catches insects with its sticky fluid, so like a liquid gum, but also actually digests and absorbs the nutriment thus derived from the soft parts of its victims. When a fly caught by the glutinous globules touches one of the glandular hairs, or we might almost call them tentacles, an irritation is set up communicable through the leaf substance to the other hairs or tentacles, which at once begin to bend in over the unfortunate insect and imprison it within a network from which escape is impossible. Then the glands begin to exude an acid digestive fluid, and the Sundew proceeds to batten and fatten upon the meat in its larder. Inorganic substances (with the exception of those which are required by plants for their sustenance, such as phosphate of ammonia, carbonate of ammonia and nitrate of ammonia) do not affect the Sundew, which possesses such extremely delicate sensibilities that it instantly recognizes the difference between organic and inorganic matter. Darwin's experiments with this plant have shown us that infinitesimal particles of vegetable or animal substance will cause the hairs to bend over, while a grain of sand leaves them uninfluenced.
Drosera longifolia, or Long-leaved Sundew, has erect elongated spatulate leaves narrowed into a long stalk, which are covered with glandular hairs like the preceding species. The white flowers grow in a terminal cluster.