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Spring 2012

Urban Jungle

The changing natural world at our doorsteps | Illustration and text by Patterson Clark      

May 8, 2012

Bulbous buttercup: A toxic invasive plant with a hint of promise

Bulbous buttercup, Ranunculus bulbosus

In May, many open lots and meadows are flecked with the sun-tracking, shiny yellow flowers of bulbous buttercup, a poisonous herb that thrives in well-drained, clay soils.

Mowing the buttercup before it sets seed won't do much to eradicate the invasive plant. Its ground-hugging leaves will continue to nourish an underground bulblike stem, or corm.

By month's end the plants will begin to wither as the corm enters dormancy for most of the summer. By autumn, the corm will have sprouted a lateral bud that will grow into a rosette of leaves, which will feed the growth of a new corm by next spring.

Bulbous buttercup corm, Ranunculus bulbosus

Bulbous buttercup is native to Europe. In France the corms were sometimes dried, cooked and eaten as a starch supplement during times of famine. The fresh plant, however, is quite toxic. Some historical accounts describe European beggars rubbing it onto their skin to raise blisters and evoke sympathy from passersby.

But even a noxious invasive weed can sound a promising note: Modern investigations of the plant's bitter toxin, protoanemonin, have revealed that the compound possesses antimicrobial properties that can inhibit growth of methicillin-resistant Staphylococcus aureus, or MRSA.

Sources:British Ecological Society, Phytotherapy Research, American Weeds and Useful Plants, Purdue University