Virginia Tech Weed Identification Guide

Corn Buttercup: Ranunculus arvensis

Weed Description:   Erect winter annual, 6 to 24 inches tall with yellow flowers.  Found primarily in the piedmonts of Virginia, Georgia, Florida, Mississippi, Tennessee, and Kentucky.

Seedling:  Cotyledons have petioles. Leaves egg-shaped in outline, with the broadest end occurring at the apex, and having toothed margins.

Stems: Erect, branching.

Fruit:  An achene, 6-8 mm long, 4-5 mm wide, covered with up to 3 mm long spines.

Flowers: Yellow in color, 5 sepals 3-5 mm long, and 5 petals 4-6.5 mm long.
Leaves:  Leaves consist of both basal and stem leaves (cauline).  Basal leaves are on long petioles, spatulate in outline with toothed margins. Stem leaves are dissected into 3-parted linear segments that are approximately 1 1/4 inches in length and 5 mm in width, without petioles, without hairs to sparsely roughly hairy.

Identifying Characteristics: The distinctive buttercup flowers and spatulate basal leaves with linear stem leaves are all characteristics that help to distinguish corn buttercup from most other similar weeds.  Several different buttercup species are common, like Bulbous Buttercup (Ranunculus bulbosus), but this weed has a thickened 'bulbous' base and does not have linear stem leaves like those of corn buttercup.