Bur Buttercup, Our Earliest Emerging Noxious and Toxic Weed

Bur buttercup growing and flowering near a sidewalk in Mountain Home, ID on March 10th, 2020.

(Photo by: Brad Stokes)

Bur buttercup, Ceratocephala testiculata Crantz, is one Elmore County’s earliest emerging and flowering weeds for homeowners, landlords, ranchers and agricultural producers. It is often the first weed to emerge and flower, growing well when daytime temperatures are between 45-50°F. This weed is native to southeastern Europe and was introduced to the United States in the early 20th century. It grows to only 4” tall near disturbed areas in Elmore County and can often be overlooked.

This weed is an annual plant in the Ranunculaceae family and is considered highly toxic to general livestock, horses and especially sheep. The bur buttercup plant contains ranunculin, a toxic compound that when crushed by livestock, horses or sheep turns into protoanemonin – a highly toxic compound that irritates mucus membranes of mammals. This poison has been known to kill livestock, horses and sheep in the western United States. Signs of protoanemonin poisoning include: anorexia, labored breathing, diarrhea, recumbency and general weakness.

Bur buttercup is fairly easy to identify (Photo 1), leaves are divided into finger-like segments resembling a bird’s foot with small fine hairs. For the full story, pick up a copy of the Mountain Home News or click on this link to subscribe to the newspaper's online edition.