Drosera


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Drosera

 

(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.

References in periodicals archive ?
Other typical herbaceous species include Drosera rotundifolia, Eleocharis spp.
Calopogon pulchellus, Drosera rotundefolia, Menyanthes trifoliata, Osmunda regalis, Potentilla palustris, Sarracenia purpurea, Triglochin maritima and Vaccinium macrocarpon are present locally.
Differential Staining with Orcein, Giemsa, CMA, and DAPI for comparative chromosome study of 12 species of Australian Drosera (Droseraceae).
Direct regeneration of Drosera from leaf explants and shoot tips, Plant Cell Tissue Organ Culture, 75: 175-178.
Study of diffused centromeric nature of Drosera chromosomes--.
If the symptoms consist of a violent, tickly cough from the chest, with retching and gagging, and pain below the ribs, which is worse at night and/or out of doors, try drosera 6c.
Phylogeny of the sundews, Drosera (Droseraceae), based on chloroplast rbcL and nuclear 18S ribosomal DNA sequences.
Love, 1982; Love & Connor, 1982; Kimber, 1984; Kimber & Yen, 1990; Singh, 1993) erroneously date the "invention" of genome analysis at Rosenberg's (1904a, 1904b, 1909) classic, turn-of-the-century study of Drosera L.
Winge was the first to suggest a hybrid origin of Drosera longifolia: "I could therefore imagine that Drosera longifolia was produced by hybridization between two species or forms with x = 10, the chromosomes of which had become added together in the zygote, and then suffered division.
His successors showed that Drosera plants fed on insects had a higher rate of plant reproduction than vegetative growth (see Oosterhuis, 1927; Lloyd, 1942).
Among dicotyledons, Boesewinkel (1989) reported a remarkably similar nucellus type in the insectivorous dicot genera Drosera and Dionaea, but not in other genera of Droseraceae.
Drosophyllum contains five times as many chloroplasts as 24 Drosera species contain on average, and about 20 times as much nDNA (Table I, note 36).