Old-field toadflax

Nuttallanthus canadensis (syn. Linaria canadensis (L.) Dumort., Antirrhinum canadenseL.; blue toadflax, Canada toadflax, old-field toadflax) is a species of Nuttallanthus in the Plantaginaceae family, native to eastern North America from Ontario east to Nova Scotia and south to Texas and Florida.

It is an annual or biennial plant growing to 25–80 cm tall, with slender, erect flowering stems. The leaves are slender, 15–30 mm long and 1-2.5 mm broad. The flowers are purple to off-white, 10–15 mm long, appearing from mid spring to late summer. It typically grows in bare areas and grassland.

It is grown as an ornamental plant in its native area. It has been introduced to western North America and Europe, and is now locallynaturalized, from Washington south to California, and also in Russia.