Rocío de sol (Drosera rotundifolia) ¿Tienes alguna duda, sugerencia o corrección acerca de este taxón? Envíanosla y con gusto la atenderemos. Foto: (c) Kristian Peters, algunos derechos reservados (CC BY-NC-SA) Ver todas las fotos etiquetadas con Drosera rotundifolia en Banco de Imagénes » Descripción de EOL Ver en EOL (inglés) → Taxon biology 1 Drosera rotundifolia (the common sundew or round-leaved sundew) is a species of sundew, a carnivorous plant often found in bogs, marshes and fens. One of the most widespread sundew species, it is generally circumboreal, being found in all of northern Europe, much of Siberia, large parts of northern North America, Korea, Japan and New Guinea. The leaves of the common sundew are arranged in a basal rosette. The narrow, hairy, 1.3–5.0 cm long petioles support 4–10 mm 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 3-5 cm, with a 5–25 cm 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 1.0–1.5 mm, light brown, slender, tapered seeds.[1] 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 its bright red colour and its 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 extracts ammonia (from proteins) and other nutrients from their bodies. The ammonia replaces the nitrogen that other plants absorb from the soil. Description 2,3 Le Rossolis à feuilles rondes (Drosera rotundifolia L.) est une espèce de la famille des Droseraceae. Bien que répartie sur l’ensemble du territoire français, sa présence n’est toujours que très locale et dépendante des tourbières qui sont des milieux écologiques de plus en plus rares. Si cette espèce est encore globalement bien représentée en zone de montagne, en plaine elle a considérablement régressé, du fait de la destruction de ses habitats de prédilection. Cette plante herbacée vivace n’excède que rarement 20 cm de hauteur. Ses feuilles sont disposées en rosette, ont une forme arrondie et sont recouvertes de poils dont l’extrémité supérieure se transforme en glande, produisant un suc collant, de 1 à 2 mm de diamètre. Les fleurs sont disposées en petites grappes, parfois rameuses. Elles éclosent de mi-juin à fin-août, et sont de couleur blanche. Le périanthe est constitué d’un calice pentamère dialysépale et d’une corolle actinomophe pentamère dialypétale et marcescente. L’androcée est formé de 5 étamines. La pollinisation est essentiellement entomophile. Le gynécée est tricarpellaire à pentacarpellaire, selon les individus, et gamocarpique. Le fruit est une capsule. Cette espèce possède des exigences écologiques très strictes. Elle ne pousse quand dans les zones de tourbières : c’est-à-dire des marais tourbeux, acides et très peu minéralisés. La disparition de ces habitats par enfrichement, leur destruction ou leur exploitation pour la récolte de la tourbe concourent à la raréfaction du Rossolis à feuilles rondes. Comme cette espèce pousse dans des milieux naturels pauvres en éléments nutritifs (en particulier les molécules azotées), celle-ci les récupère directement sur des insectes qu’elle piège : le Rossolis à feuilles rondes est une plante carnivore. Les poils glanduleux situés sur les feuilles collent et digèrent des petites diptères et des fourmis, ce qui apporte à la plante les éléments qui lui sont nécessaires et qui ne sont pas présents dans le substrat sur lequel elle pousse. Le Rossolis à feuilles rondes possède des propriétés antitussives : il est encore largement utilisé dans de nombreuses préparations pharmaceutiques. Il peut se confondre avec d’autres espèces du genre Drosera, mais c’est le seul à présenter des feuilles arrondies, alors que les autres plantes proches possèdent des feuilles plus ou moins allongées. Référence bibliographique principale : COSTE H. – 1900-1906. Flore descriptive et illustrée de la France, de la Corse et des contrées limitrophes. Tome I. Paul-Klincksieck, Paris. Réédition en 1998 par la Librairie scientifique et technique Albert Blanchard, Paris : 416 pp. National distribution 4 Canada Ori gi n : Native R egu l ari ty : Regularly occurring Cu rren tl y : Present Con fi d en ce : Confident United States Ori gi n : Native R egu l ari ty : Regularly occurring Cu rren tl y : Present Con fi d en ce : Confident Description 5 More info for the term: adventitious Round-leaved sundew is an insectivorous, short-lived perennial forb arising from a basal rosette of leaves. The upper surface of the leaf blades are covered with reddish, glandular hairs tipped with a sticky, glutinous secretion that traps insects. The inflorescence is a one-sided raceme with 2 to 15 flowers on a scape that is 2 to 10 inches (5-25 cm) long. There may be one to seven inflorescences per rosette. The fruits are capsules with numerous small seeds [8,20,21,41,44]. The root system of round-leaved sundew is usually shallow (less than 2.4 inches [6 cm]) [8]. It consists of a taproot - functional for less than a year - which is replaced by mostly horizontal adventitious roots with a few root hairs [8,37,50]. Round-leaved sundew compensates for the low available nutrients in its habitat by catching and digesting insects [8,45,49,54]. Insects are caught with the sticky glandular leaf hairs, and the leaf then folds around the prey. The hairs secrete proteolytic enzymes which digest the insect and enable the plant to absorb nutrients through its leaves [37,45,52]. Insect capture is generally believed to enhance growth and reproduction of round-leaved sundew [8,24,29,46,56]. It is significantly correlated (p less than 0.01) with total leaf number, number of new leaves formed, and total leaf area [46]. However, Stewart [50] determined that round-leaved sundew did not benefit from insect capture in field experiments in the Jefferson National Forest, Virginia. The benefits of insectivory may be site-dependent; round-leaved sundew may benefit most from insect capture on the most nutrient-poor sites. Synonym 6,7 Drosera rotundifolia var. furcata Y. Z. Ruan. Habitat characteristics 5 More info for the terms: bryophyte, graminoid, peat, swamp Round-leaved sundew is most often found in bogs, but also grows in swamps, rotting logs, mossy crevices in rocks, or damp sand along stream, lake, or pond margins [31,37,39,52,59]. It is generally associated with sphagnum mosses and grows on floating sphagnum mats or sphagnum hummocks [8,29,32,37,50]. It may also grow on peat soils of other bryophyte or of graminoid origins [1]. In the northern part of its range the sphagnum bogs in which round-leaved sundew grows are generally found surrounding glacial lakes. In the Appalachians from Pennsylvania to Alabama, the bogs are most often at confluences of springheads, around seeps, or along streams rather than lake margins. The same is true for sphagnum bogs of the southeastern coastal plain, but there round-leaved sundew may also grow in grass-sedge bogs. In the Pacific Northwest, sphagnum bogs are typically found along streams and occasionally develop around high elevation seeps and shallow lake margins in the northern Rocky Mountains [3,45]. Round-leaved sundew is usually confined to sites with a high water table or high precipitation and humidity [8]. It requires continually moist or wet situations [20]. Round-leaved sundew grows in organic acid soils that are low in available nutrients (nitrogen and phosphorous, and calcium [3,24,49,54]. According to Crowder [8], the normal range of the water table on sites where round-leaved sundew grows is from 1 inch (2 cm) above to 16 inches (40 cm) below the soil surface. Flooding can be tolerated for several weeks, but dry periods can only be tolerated for a very short time. Lloyd [37] reported that it is not found on limestone soils; high calcium concentrations may be toxic to the plant. Round-leaved sundew grows in sedge meadow communities of the Huntingdon Marsh in Quebec on peat underlain by clay at 24 inches (60 cm) or more. The soil surface is slightly above or up to 10 inches (25 cm) below the water table [2]. Round-leaved sundew has been reported as growing on sites ranging from neutral pH (7.3) to very acidic (3.2) [18,38]. Acidic soils with low nutrient concentrations (nitrogen, phosphorous, or calcium) seem to be the most common substrate [2,11,38,49,61]. In British Columbia, round-leaved sundew is an indicator of wet to very wet, nitrogen-poor soils in boreal, cool temperate, and cool mesothermal climates. It is associated with sphagnum moss in nonforested, semiterrestrial communities [28]. An atypical site was found on Ile Perrot, Quebec, where round-leaved sundew was growing on moderately dry, abandoned pastureland that originally had been a swamp. The soil was well-drained loamy sand with an average pH of 6.1. The site was "basically infertile" with extremely low calcium and nitrogen concentrations [52]. Associations 8 In Great Britain and/or Ireland: Animal / predator leaf of Drosera rotundifolia is predator of Diptera Other: major host/prey Animal / predator leaf of Drosera rotundifolia is predator of Coenonympha pamphilus Other: unusual host/prey Animal / predator bladder of Drosera rotundifolia is predator of Anisoptera Other: unusual host/prey Fire management considerations 5 More info for the terms: bog, marsh Periodic autumn fires can prolong the life of some bogs by inhibiting the invasion of woody plant species [45]. Round-leaved sundew, along with cattails (Typha spp.), horsetails (Equisetum spp.), and common buckbean, are present in sedge meadow communities that are maintained by fire in the Huntingdon Marsh, Quebec. Fire is used to prevent the invasion of alders and willows [2]. In central Alberta, the burning of bog forests may revert the vegetation to that of Labrador tea (Ledum spp.)-dominated moors, of which round-leaved sundew is a component [36]. Phenology 5 More info on this topic. More info for the term: hibernaculum Round-leaved sundew generally flowers from June to September throughout its range [19,30,39,45]. Flowers open one per day, starting from the bottom of the inflorescence [50]. Seed dispersal begins in July and most seeds fall before winter. However, some may be found in dried capsules in the spring [8]. Round-leaved sundew forms a hibernaculum (tightly rolled leaf primordia) in the fall. The remaining leaves, and frequently the roots, die back after the hibernaculum develops. The hibernaculum opens in April or May of the following year [45,55,62]. Barcode data: drosera rotundifolia 9 The following is a representative barcode sequence, the centroid of all available sequences for this species. National nature serve conservation status 4 Canada R ou n d ed N ati on al Statu s R an k : N5 - Secure United States R ou n d ed N ati on al Statu s R an k : N5 - Secure Management considerations 5 More info for the terms: bog, natural, peat Clearing and drainage of peat bogs or swamps for peat mining, millpond construction, access to timber, and agricultural purposes have resulted in the decline of round-leaved sundew habitat by altering site conditions in many areas [1,8,10,35,45]. Drainage also has an indirect negative effect by diminishing the numbers of round-leaved sundew prey that have aquatic larval stages [8]. Insectivorous plants, including round-leaved sundew, may add to the nutrient pool on the nutrient-deficient sites where they most often grow [40]. Round-leaved sundew itself apparently does not respond positively to fertilization. The application of nitrogen, phosphorous, or a combination of the two to nutrient-poor sites negatively affected the growth of a natural round-leaved sundew population on the Jefferson National Forest, Virginia. Plants were not as large, did not have as many mature leaves, and did not produce as many flowers as plants on sites without added nutrients. The negative effect may have been the product of ion toxicity [50]. Microhabitat segregation among different sundews (Drosera spp.) at the same site may influence the types of prey captured. Round-leaved sundew and spatulate-leaved sundew (D. intermedia) in southern Germany occupied different microhabitats and caught different kinds of insects, even though they occurred together in the same bog [55]. Lists of insects that have been captured as prey in the leaves of round-leaved sundew are available [8,26,55]. Grazing apparently does not eradicate round-leaved sundew; it has been found on wet grasslands of the British Isles that have been grazed by both cattle and sheep [8]. Other uses and values 5 More info for the term: fresh Leaves of round-leaved sundew can curdle milk and were used in Sweden to make cheese. Fresh leaves have also been used to treat warts. Round-leaved sundew has been used as a remedy for respiratory ailments. The plant contains an antibiotic effective against Streptococcus, Staphylococcus, and Pneumococcus bacteria [43]. Taxonomy 4 Commen ts : Accepted by Kartesz (1999) with three North American varieties recognized. References 1. © Wikipedia editors and contributors, some rights reserved 2. Muséum national d'Histoire naturelle [Ed]. 2003-2014. Inventaire national du Patrimoine naturel, site Web : http://inpn.mnhn.fr. 3. © Muséum national d'Histoire naturelle. Service du Patrimoine naturel, some rights reserved 4. © NatureServe, some rights reserved 5. Matthews, Robin F. 1994. Drosera rotundifolia. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ 6. Flora of China Vol. 8: 200 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008. 7. © Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA, some rights reserved 8. © BioImages, some rights reserved 9. © Barcode of Life Data Systems, some rights reserved