Ranunculus

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Ranunculus
Ranunculus macro.jpg
Creeping buttercup (Ranunculus repens)
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
Order: Ranunculales
Family: Ranunculaceae
Genus: Ranunculus
L.
Species

250-400+; see text

Ranunculus /ræˈnʌŋkjʊləs/[1] is a large genus of about 600 species of plants in the Ranunculaceae. Members of the genus include the buttercups, spearworts, water crowfoots and the lesser celandine.

They are mostly herbaceous perennials with bright yellow or white flowers (if white, still with a yellow centre); some are annuals or biennials. A few species have orange or red flowers. There are usually five petals, but sometimes six, numerous, or none, as in R. auricomus. The petals are often highly lustrous, especially in yellow species. Buttercups usually flower in the spring, but flowers may be found throughout the summer, especially where the plants are growing as opportunistic colonizers, as in the case of garden weeds.

The Water crowfoots (Ranunculus subgenus Batrachium), which grow in still or running water, are sometimes treated in a separate genus Batrachium (from Greek βάτραχος batrachos, "frog"). They have two different leaf types, thread-like leaves underwater and broader floating leaves. In some species, such as R. aquatilis, a third, intermediate leaf type occurs.

Ranunculus species are used as food plants by the larvae of some Lepidoptera species including Hebrew Character and Small Angle Shades. Some species are popular ornamental flowers in horticulture, with many cultivars selected for large and brightly coloured flowers.

Ranunculus glacialis, one of the white-flowering species
Persian buttercup blooming outside Conservatory of Flowers
Seed head of Ranunculus showing developing achenes

Naming[edit]

The name Ranunculus is Late Latin for "little frog," from rana "frog" and a diminutive ending. This probably refers to many species being found near water, like frogs.

The name buttercup may derive from a false belief that the plants give butter its characteristic yellow hue (in fact it is poisonous to cows and other livestock). A popular children's game involves holding a buttercup up to the chin; a yellow reflection is supposed to indicate fondness for butter.[2]

In the interior of the Pacific Northwest of the United States the buttercup is called "Coyote’s eyes" — ʔiceyéeyenm sílu in Nez Perce and spilyaynmí áčaš in Sahaptin. In the legend Coyote was tossing his eyes up in the air and catching them again when Eagle snatched them. Unable to see, Coyote made eyes from the buttercup.[citation needed]

Splitting of the genus[edit]

Molecular investigation of the genus has revealed that Ranunculus is not monophyletic with respect to a number of other recognized genera in the family – e.g. Ceratocephala, Halerpestes, Hamadryas, Laccopetalum, Myosurus, Oxygraphis, Paroxygraphis and Trautvetteria. A proposal to split Ranunculus into several genera have thus been published in a new classification for the tribe Ranunculeae.[3] The split (and often re-recognized) genera include Arcteranthis Greene, Beckwithia Jeps., Callianthemoides Tamura, Coptidium (Prantl) Beurl. ex Rydb., Cyrtorhyncha Nutt. ex Torr. & A.Gray, Ficaria Guett., Krapfia DC., Kumlienia E.Greene and Peltocalathos Tamura.

Toxicity[edit]

All Ranunculus species are poisonous when eaten fresh by cattle, horses, and other livestock, but their acrid taste and the blistering of the mouth caused by their poison means they are usually left uneaten. Poisoning can occur where buttercups are abundant in overgrazed fields where little other edible plant growth is left, and the animals eat them out of desperation. Symptoms include bloody diarrhea, excessive salivation, colic, and severe blistering of the mucous membranes and gastrointestinal tract. When Ranunculus plants are handled, naturally occurring ranunculin is broken down to form protoanemonin, which is known to cause contact dermatitis in humans and care should therefore be exercised in extensive handling of the plants.[4] The toxins are degraded by drying, so hay containing dried buttercups is safe.

Selected species list[edit]

See List of Ranunculus species for a more complete list with native ranges.

See also[edit]

References[edit]

Notes[edit]

  1. ^ Sunset Western Garden Book, 1995:606–607
  2. ^ Roadside Plants and Flowers: A Traveler's Guide to the Midwest and Great Lakes Area : With a Few Familiar Off-Road Wildflowers, North Coast Bks, Marian S. Edsall, Univ of Wisconsin Press, 1985 ISBN 0299097048
  3. ^ Emadzade K, Lehnebach C, Lockhart P & Hörandl E (2010) A molecular phylogeny, morphology and classification of genera of Ranunculeae (Ranunculaceae). Taxon 59: 809–828.
  4. ^ "Ranunculus". Botanical Dermatology Database. Retrieved October 18, 2013. 
  5. ^ Li, H. (December 2013). "Evaluation of antiviral activity of compounds isolated from Ranunculus sieboldii and Ranunculus sceleratus". Planta Medica 71 (12): 1128–1133. PMID 16395649. 

Sources[edit]

  • "GRIN Species Records of Ranunculus". Germplasm Resources Information Network (GRIN). United States Department of Agriculture, Agricultural Research Service, Beltsville Area. Retrieved 2008-01-08. 

External links[edit]