- Latin Name: Nuttallanthus texanus
- Family: Plantaginaceae
- Common Names: blue toadflax, Texas toadflax, wild toadflax, large-flowered toadflax.
- Synonyms/Misapplications: Linaria canadensis var. texanus, Linaria texana
- Codon: NUTCAN
|photo by Rod Gilbert, also featured on Main Page|
|Genus:|| Nuttallanthus D.A. Sutton|
|Species:|| Nuttallanthus texanus (Scheele) D.A. Sutton|
Native or biennial herb, growing upright, 1-6 dm. tall. Produces decumbent side shoots which do no flower.
Cauline and basal leaves are narrow to obtuse, and glabrous.
Inflorescence glandular-puberulent, flowers blue to violet, borne alternately in a raceme.
Sepals 5, basally connate.
Each corolla is bilabiate with a smaller upper lip and a tri-lobed lower lip with a slender, curved nectar spur. There is a white ridge in the center of the lower corolla lobe. 
Seeds prominently covered in tubercules, edges sharp.
In contrast, N. canadensis, with which it is often confused, has smaller flowers, 8-10 mm, with a 2-6 mm spur (N. texana has a 10-12 mm long, and a 2-6 mm. spur), and nearly smooth seeds.
West Cascades, southwest BC to California, and southern and central US.
It is rare in Washington, known from a few number of extant populations.
Glacial outwash prairies, or disturbed areas with a sandy or gravelly substrate, areas with very little organic matter in the soil. Low elevations in Washington. Associated species include red fescue (Festuca rubra), hairy cat's ear (Hypochaeris radicata), upland larkspur (Delphinium nuttallii).
A source of pollen for a variety of butterfly species.
- Bowcutt, F., & Hamman, Sarah. (2016). Vascular plants of the South Sound prairies (First ed.). Olympia, Washington: The Evergreen State College Press.
- Hitchcock, C. L., Cronquist, A., Giblin, D., & Legler, B. et al. (2018). Flora of the Pacific Northwest: an illustrated manual. Seattle: University of Washington Press.
- Rare Plant Field Guide: WA - DNR. Retrieved from https://www.dnr.wa.gov/NHPfieldguide
- WTU Herbarium, Burke Museum, & University of Washington. Retrieved from https://biology.burke.washington.edu/herbarium/imagecollection/taxon.php?Taxon=Nuttallanthus%20texanus
- Butterfly Garden Plants: Texas Toadflax. (2019). Retrieved from http://nababutterfly.com/texas-toadflax/