Drosera rotundifolia

Drosera rotundifolia, the round-leaved sundew or common sundew, is a species of sundew, a carnivorous plant often found in bogs, marshes and fens. One of the most widespread sundew species, it has a circumboreal distribution, being found in all of northern Europe, much of Siberia, large parts of northern North America, Korea and Japan but is also found as far south as California, Mississippi and Alabama in the United States of America and on New Guinea. The leaves of the common sundew are arranged in a basal rosette. The narrow, hairy, 1.3-to-5.0-centimetre (0.51 to 1.97 in) long petioles support 4-to-10-millimetre (0.16 to 0.39 in) long laminae. The upper surface of the lamina is densely covered with red glandular hairs that secrete a sticky mucilage. A typical plant has a diameter of around 3 to 5 centimetres (1.2 to 2.0 in), with a 5-to-25-centimetre (2.0 to 9.8 in) tall inflorescence. The flowers grow on one side of a single slender, hairless stalk that emanates from the centre of the leaf rosette. White or pink in colour, the five-petalled flowers produce 1.0-to-1.5-millimetre (0.039 to 0.059 in), light brown, slender, tapered seeds. In the winter, D. rotundifolia produces a hibernaculum to survive the cold conditions. This consists of a bud of tightly curled leaves at ground level. The plant feeds on insects, which are attracted to the 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 that 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, and plants that are placed in a high-nitrogen environment rely less upon nitrogen from captured insects. It has been assumed that insects were also attracted to the bright red color of the common sundew, but studies using artificial traps have suggested that color does not affect prey attraction. In North America, the common sundew is found in all parts of Canada except the Canadian Prairies and the tundra regions, southern Alaska, the Pacific Northwest, and along the Appalachian Mountains south to Georgia and Louisiana. It is found in much of Europe, including the British Isles, most of France, the Benelux nations, Germany, Denmark, Switzerland, Czech Republic, Poland, Belarus, the Baltic countries, Sweden and Finland, as well as northern portions of Portugal, Spain, Romania, mountain regions of Bulgaria and in Iceland and southern regions of Norway and Greenland. It is infrequent in Austria and Hungary, and some populations are scattered around the Balkans.