Other common names
Curveseed butterwort, little bur, testiculate buttercup
A small, 2‐ to 5‐inch tall plant that grows and flowers early in spring, bur buttercup produces stiff burrs that help spread this weed. It is toxic to livestock.
Typical plant growing in disturbed site. Photo courtesy of Gary A. Monroe @ USDA‐NRCS PLANTS Database.
Grayish‐green, hairy, and attached at the base of the plant. Leaf blades look like fingers.
The leaves are small and fingerlike. Photo by S. Donaldson.
Short; extend outward from the base of the plant.
The seeds form in stiff burrs that turn brown in color when mature. Photo by S. Donaldson.
Small, yellow, with 2 to 5 petals. Blooms from late winter to early spring.
Flowers are small, yellow and have 2 to 5 petals. Photo courtesy of Dr. Clinton C. Shock, Oregon State University.
Forms many stiff, brown burrs. This is the point at which most people notice the plant.
Seedlings have divided leaves that look like fingers. Photo courtesy of Dr. Clinton C. Shock, Oregon State University.
Eurasia; naturalized throughout much of the western United States
Where it grows
Roadsides, vacant lots, in pavement cracks and other disturbed or unmanaged sites
Winter annual (sprouts in fall and early winter)
Reproduces by seed
Bur buttercup should be controlled prior to seed formation. As this occurs very early in the spring, careful monitoring is needed to stop the spread of this weed.
Dig, hoe or pull young seedlings. Use mechanical control methods prior to formation of flowers and burrs.
Thick mulches can help prevent seed germination. Plant desirable vegetation that will shade the area and reduce germination and growth of young plants.
Apply broadleaf‐selective herbicides on young plants. Pre‐emergence herbicides can be used to manage existing seed banks.
DiTomaso, J.M. and E.A. Healy. 2007. Weeds of California and Other Western States. University of California Publication 3488.
USDA‐NRCS Plants Database. No date. Ceratocephala testiculatus (Crantz) Roth, Curveseed Butterwort, USDA.
Utah State University Cooperative Extension. 2010. Bur Buttercup. Range Plants of Utah, USU.
Whitson, Tom D. (editor). 2002. Weeds of the West. University of Wyoming, Jackson, Wyoming.