linaria vulgaris

ND Noxious & Troublesome Weeds

toadflax

Yellow Toadflax
(Linaria genistifolia spp. dalmatica)

State Noxious Weed List -No

Growth form: Escaped perennial ornamental from Eurasia which often grows over 3 feet tall.

The plant is distinguished by the bright yellow “snapdragon” flowers which have an orange colored throat and a long spur.

The weed spreads by both a creeping root system and seed. The roots of a single plant can spread laterally over 10 feet and give rise to daughter plants every few inches. Also, a single plant may produce over 500,000 seeds which are disk shaped and 0.08 inch in diameter.

Yellow toadflax can be mildly poisonous to livestock that graze it. Often the origins of an infested area can be traced to an escape from a horticultural planting.

The leaves are long and narrow attached to a narrow stem, similar to leafy spurge which helps distinguish it from the more broad-leaved dalmatian toadflax.