Drosera(redirected from droseras)
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Related to droseras: sundew plant
(sundew), a genus of insectivorous plants of the family Droseraceae. The plants are perennial and, less often, annual herbs. They have a creeping or tuberous rhizome and rosettes of round or elongate leaves. The leaves are covered with glandular hairs having a red glandular capitulum that secretes a sticky substance. The hairs, which are easily stimulated, entrap insects. The liquid secreted by the glands contains organic acids and pepsins that decompose the proteins in the captured prey. In this way the plant makes up for the nutrient deficiency characteristic of plants on marshy soils. The pentamerous flowers are solitary or in racemes. The fruit is a dehiscent capsule, which opens along three to five valves.
There are approximately 100 species, distributed in the tropical and temperate zones of both hemispheres. Most of the species are found in Australia and New Zealand. Droserapygmaea, which grows in Tasmania, is the smallest flowering plant. It is 1–2cm tall, and its leaves are approximately 2 mm long. Four species are found in the USSR: D. rotundifolia, D. anglica, D. intermedia, and D. obovata.