Butter-and-Eggs
Linaria vulgaris
Butter-and-Eggs (Linaria vulgaris), also called yellow toadflax, is a perennial weed from Europe with spikes of spurred, two-lipped yellow flowers that have an orange center. On the Great Plains it blooms from June into August, and it grows mostly on roadsides, fields and other disturbed ground. Photographed in the Black Hills.
| Family | Plantaginaceae · Plantain |
|---|---|
| Status | Introduced perennial |
| Blooms | June into August |
| Height | 30–90 cm (12–36 in) |
| Where | Roadsides, fields, railways and other disturbed ground |
| Also called | Yellow Toadflax |
| Listed | Locally noxious in Custer (2022–2026) and Pennington (2026–2030) counties, South Dakota (as yellow toadflax). State designated noxious weed in Wyoming. |
Roots, seeds & germination
Root: A taproot that can reach about 1 m (3.3 ft) deep, with long side roots. Shoots rise from buds on the roots, and root pieces as short as 1 cm can regrow.
Seed: Seeds are about 2 mm long with a broad wing. Most fall close to the parent plant, and dormancy of up to 8 years has been reported.
Germination: Rates vary but are usually low. Seeds sprout on the surface or in the top 2–3 cm of soil. About 8 weeks of wet stratification (holding seed damp before it sprouts) and light both help.
How do you identify Butter-and-Eggs?
Look for snapdragon-like yellow flowers with an orange center and a long, narrow spur, on stems crowded with narrow, hairless leaves that don't clasp the stem. Dalmatian toadflax has very similar flowers, but its leaves are broad and clasp the stem.
When does it bloom?
June into August.
Where does it grow?
Mostly on agricultural land, roadsides, railways and other disturbed sites. In many parts of North America it is infrequent except where the ground has been cultivated.
Other flowers to compare
Sources: Fire Effects Information System: Linaria spp.; Minnesota Wildflowers: Butter and Eggs; South Dakota DANR: Locally Noxious Weed Pest List; Custer County, SD: Noxious Weeds; University of Wyoming: Yellow Toadflax.