Toadflax is a type of plant with flowers shaped much like those of snapdragons. Toadflax flowers are tube-shaped and have two lips. Each flower also has a long, spurlike part in which nectar is stored. There are many species (kinds) of toadflax..
Common toadflax, also called butter and eggs, grows 1 to 21/2 feet (30 to 76 centimeters) tall. It has showy yellow flowers that grow in a cluster at the top of the stem. The mouth of the flower tube is closed by a thick, orange ridge on the lower lip. The weight of a bee looking for nectar forces the mouth of the tube open. Common toadflax was introduced to North America from Europe. It is easy to grow in gardens from seed or parts of rhizomes (underground stems), but it can become a nuisance because it spreads quickly. Old field toadflax, also called blue toadflax or Canada toadflax, is native to North America. It has small blue flowers and is smaller than the common toadflax. Both species grow as weeds in fields and along roads.