Ranunculus acris is a species of flowering plant in the family Ranunculaceae, and is one of the more common buttercups across Europe and temperate Eurasia. Common names include meadow buttercup,
Description
Ranunculus acris is a
herbaceous perennial plant that grows to a height of , with ungrooved flowing stems bearing glossy yellow
flowers about 25 mm across. There are five overlapping
borne above five green
held upwards against the petals, that turn yellow as the flower matures. It has numerous
inserted below the ovary. The leaves are compound, with finely cut, hairy, leaflets.
Unlike
Ranunculus repens, the terminal leaflet is sessile. As with other members of the genus, the numerous seeds are borne as
.
The rare autumn buttercup ( R. aestivalis) is sometimes treated as a variety of this species.[ USDA Plants Profile: R. aestivalis.]
The juice of the plant is semi-poisonous to livestock, causing blistering.
Distribution
The plant is native to Eurasia, but has been introduced across much of the world so that it now has a circumpolar distribution.
It is a naturalized species and often a weed in parts of North America,
but it is probably native in
Alaska and
Greenland.
[ Flora of North America] In
New Zealand it is a serious pasture weed costing the dairy industry hundreds of millions of dollars.
It has become one of the few pasture weeds that has developed a resistance to herbicides.
Ecology
R. acris is a species characteristic of grazed or mown neutral
grassland communities, tending to occupy areas where drainage conditions are intermediate between those favoured by
R. bulbosus in drier soils, and
R. repens in wetter soils.
[Harper JL. 1957. Ranunculus acris L. Journal of Ecology 45(1): 289 – 342.] Its abundance is said to be an indicator of grassland age and continuity but does not appear to be a good competitor in species-rich communities dominated by tall grasses.
[Jacobs J. Graves M, Mangold J. 2010. Ecology and management of tall buttercup ( Ranunculus acris L.). Bozeman, Montana: United States Department of Agriculture, Natural Resources Conservation Service]
The flower buds begin developing in late summer in the year before flowering. Floral development is promoted by low winter temperatures, and the plant passes the winter in a rosette form with small green leaves that appear to resist the ravages of frost.
Cultivation
In horticulture the species may be regarded as a troublesome weed, colonising lawns and paths. However, it may be a welcome feature of wildflower meadows. The double-flowered
cultivar R. acris 'Flore Pleno' has gained the Royal Horticultural Society's Award of Garden Merit.
Toxicity
Oils in the plant, probably present in the leaves and stems, contain the
glycoside ranunculin, which when ingested can cause abdominal pains and intestinal disorders.
When eaten by animals, the buttercups have caused blistering of the tongue and lips, diarrhea and blindness.
Other symptoms of poisoning include ventricular fibrillation and respiratory failure.
Uses by Native Americans
The
Abenaki smash the flowers and leaves and sniff them for headaches.
[Rousseau, Jacques 1947 Ethnobotanique Abenakise. Archives de Folklore 11:145-182 (p. 166)] The
Nuxalk Nation apply a poultice of pounded roots to
boils.
[Smith, Harlan I. 1929 Materia Medica of the Bella Coola and Neighboring Tribes of British Columbia. National Museum of Canada Bulletin 56:47-68 (p. 57)] The Micmac use the leaves for headaches.
[Chandler, R. Frank, Lois Freeman and Shirley N. Hooper 1979 Herbal Remedies of the Maritime Indians. Journal of Ethnopharmacology 1:49-68 (p. 60)] The
Innu people inhale the crushed leaves for headaches.
[Speck, Frank G. 1917 Medicine Practices of the Northeastern Algonquians. Proceedings of the 19th International Congress of Americanists Pp. 303-321 (p. 315)]
The Cherokee use it as a poultice for abscesses, use an infusion for oral thrush, and use the juice as a sedative.[Hamel, Paul B. and Mary U. Chiltoskey 1975 Cherokee Plants and Their Uses -- A 400 Year History. Sylva, N.C. Herald Publishing Co. (p. 31)] They also cook the leaves and eat them as greens.
The Iroquois apply a poultice of the smashed plant to the chest for pains and for colds, take an infusion of the roots for diarrhea,[Herrick, James William 1977 Iroquois Medical Botany. State University of New York, Albany, PhD Thesis (p. 320)] and apply a poultice of plant fragments with another plant to the skin for excess water in the blood.[Rousseau, Jacques 1945 Le Folklore Botanique De Caughnawaga. Contributions de l'Institut botanique l'Universite de Montreal 55:7-72 (p. 42)]
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