Appearance
Linaria vulgaris is a perennial herb that can reach 3.3 ft. (1 m) tall with erect, smooth stems that emerge in clumps from a spreading root system.
Foliage
Leaves are nearly sessile, drooping, linear and 1-2 in. (2.5-5 cm) long. Leaves can sometimes be sparsely covered by long hairs.
Flowers
Flowering occurs from May to September, when yellow/white, snapdragon-like flowers develop. Flowers, including the spur, are 0.6-1.2 in. (1.5-3 cm) long and occur in racemes at the apex of the stems.
Fruit
Fruits are capsules that are 0.4-0.5 in. (9-12 mm) long. Each capsule contains small, flat blackish seeds with a papery wing.
Ecological Threat
Linaria vulgaris occurs in fields, pastures, roadsides, undisturbed prairies and rangelands. It is native to Europe and was introduced into North America, as an ornamental, in the mid 1600s.