Sunday, July 3, 2011

The Scilly buttercup

Scilly buttercup (Ranunculus muricatus)
The Scilly buttercup is a species of buttercup which is sometimes also known as the spiny-fruit buttercup. It is native to Europe, but it can be found in many other places in the world, including parts of Africa, Australia, and the western and eastern United States, as an introduced species and agricultural and roadside weed. It grows in wet habitats, such as irrigation ditches. 

In Malta it is found in humid valley bottoms such as at Chadwick Lakes and Fiddien. It is an annual or sometimes biennial herb producing a mostly hairless stem up to half a meter long which may grow erect or decumbent along the ground.

The buttercups belong to a large genus of plants that can be found almost throughout the world. It consists of about 400 species some of which are terrestrial while others are aquatic. In the genus, known as Ranunculus, we also find the spearworts, water crowfoots and the lesser celendine. 

The name Ranunculus derives from the Latin words rana (frog) and ulus (little). This probably refers to many species being found near water, like frogs. Most buttercup species are poisonous when eaten by sheep, and other livestock but they are left alone because they have a bitter taste and have a blistering effect on the mouth caused by the poison.

Most of the species have bright yellow or white flowers. If the flowers are white they have a yellow center. In many species the petals are highly lustrous making it difficult to photograph them especially in direct sunlight.

In Malta at least 13 species have been recorded some of which are aquatic and can be found floating in pools and streams especially in the numerous small pools found in the rocky habitat known as garigue.

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 excessive handling of the plants. The toxins are degraded by drying, so hay containing dried buttercups is safe.

This article was published in The Times on 13.04.2011

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