|Nuttallanthus canadensis (Canada Toadflax)|
Nuttallanthus is a genus of four species of herbaceous annuals and perennials that was traditionally placed in the foxglove family Scrophulariaceae. Due to new genetic research, it has now been placed in the vastly expanded family Plantaginaceae. Three species of Nuttallanthus are native to North America and one to South America. Nuttallanthus was until the 1980s included in a wider circumscription of the genus Linaria, a genus now considered restricted to the Old World.
- Nuttallanthus canadensis (Canada Toadflax or Oldfield Toadflax)
- Nuttallanthus floridanus (Apalachicola Toadflax)
- Nuttallanthus texanus (Texas Toadflax)
Canada Toadflax (Nuttallanthus canadensis, syn. Linaria canadensis) is native to eastern North America, in southern Canada and the United States. It is a purple to blue, weedy species, which blooms early in the spring. It is an important nectar source for spring buildup of honeybees, because the plants are often so thick in fields, and they bloom so early.
The North American species do not appear to form interspecific hybrids at all. The most common mode of reproduction is self-fertilization, with occasional fertilization by another plant of the same species.
- Crawford, P. T.; Elisens, W. J. (2006), "Genetic variation and reproductive system among North American species of Nuttallanthus (Plantaginaceae)", American Journal of Botany, 93 (4): 582–91, PMID 21646219, doi:10.3732/ajb.93.4.582