Description:

YELLOW TOADFLAX — Linaria vulgaris Mill.

Scrophulariaceae — (Figwort family)

Yellow toadflax (commonly known as “butter and eggs”) is perennial, one to two feet tall, reproducing by seed and underground rootstocks. Leaves are pale green, numerous, narrow, pointed at both ends, two and a half or more inches long. Flowers have bright yellow spurs that are one inch long with a bearded, orange throat. Fruit is round, ¼ inch in diameter, brown, two-celled, with many seeds. Seeds are dark brown to black, 1/2 inch in diameter, flattened with a papery circular wing.

Yellow toadflax is a native of Eurasia, introduced to the United States in the mid-1800s as an ornamental. This creeping perennial is an aggressive invader of rangelands, displacing desirable grasses. It is also found along roadsides, waste places and cultivated fields. An extensive root system makes this plant difficult to control. It can also easily be transplanted with other flowers and plants on accident when trading perennial plant materials within a landscape or with friends.

CAUTION: Yellow Toadflax contains a poisonous glucoside that may be harmful to livestock.

Nonstandard name: butter and eggs.

Growth Habit: Perennial, often over 3` tall.

Leaves: Long and narrow, numerous, pale green, smooth and pointed, attached directly to the stem.

Stem: Smooth, erect and sometimes branched.

Flower: Snapdragon type, 1 to 1½" long with spur, bright yellow with deep orange center.

Roots: Woody, vigorous, well branched with many laterals.

Seeds: Round ½" in diameter, dark brown to black with a papery circular wing.

(Courtesy of Weeds of the West)

Control Strategies:

The extensive root system on this plant make it extremely difficult to control by hand pulling, cultivation, or digging. It is also resistant to most herbicides. Since this weed is an escaped ornamental plant it is often found in lawns or flower beds where the use of Tordon is precluded.  Roundup applied with a paint brush can selectively remove this weed from those sites with careful application. On rangeland sites, Tordon at 1 to 2 quarts per acre in the fall is the most effective treatment.    

To learn about biological control for Yellow Toadflax visit this link.