Linaria canadensis (Old-field Toadflax)
|Also known as:||Blue Toadflax, Canada Toadflax|
|Life cycle:||annual, biennial|
|Habitat:||sun; dry sandy soil, prairies, roadsides|
|Bloom season:||May - July|
|Plant height:||4 to 20 inches|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Flowers are in a spike-like raceme at the top of the stem that elongates up to 8 inches. Individual flowers average about 1/3 inch long, irregular with an upper lip divided into 2 erect rounded lobes, and a lower lip with 3 rounded lobes. Flower color is blue to blue-violet, with a 2-humped white spot at the base of the lower lip. There is usually 1 spike on a stem, but a plant may have multiple stems.
Leaves and stem:
Leaves are 1 to 1½ inches long and very narrow—not more than 1/8 inch wide, toothless, hairless, with pointed tips and no leaf stalk. They are alternately attached and narrower on flowering stems, but oppositely attached and broader on the shorter non-flowering stems. The main stem is smooth and slender, green to reddish brown.
With its small flowers and foliage and slender stems, it is easy to miss unless there is a clump of plants together. This species frequently goes by Nuttallanthus canadensis but the accepted name in Minnesota is Linaria canadensis. Formerly in the figwort family (Scrophulariaceae) is has been reassigned to the plantain family (Plantaginaceae).
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Photos by K. Chayka taken at Wild River State Park, Chisago County.
Have you seen this plant in Minnesota, or have any other comments about it?