Dalmatian toadflax, Linaria dalmatica (L.) P. Mill. ssp. dalmatica (Fig. 1a), and yellow toadflax, Linaria vulgaris (L.) P. Mill. (Fig. 1b), are exotic [see Glossary] weeds of rangeland, forests and cropland. Although several species of weedy toadflax have been intentionally or accidentally introduced to North America, these two species are by far the most common and problematic for land managers. Both species are known to thrive particularly well in disturbed, open habitats, are most competitive, and can easily dominate native or desirable plant communities in areas characterized by dry summers.