Canada toadflax

Family

Scrophulariaceae

Scientific Name

Linaria canadensis

Other Common Names:

old-field toadflax

Synonyms (former Scientific Names):

Linaria canadensis

Habit

Grows from 6-24 inches tall and blooms from April to September.

Leaves

Stems are up to 50 cm tall, erect, single or multiple from base, and typically simple or branching. Leaves of flowering stems are alternate, linear, and wispy, up to 3.5 cm long and 3 mm wide, with margins slightly thickened.

Identifying Characteristics

It is identified by its irregular blue flowers, its small thin leaves, and its basal spurs.

Flower Seed Head

Flowers are 1/4-1/2 inch long, pale blue-purple with lighter palate, small, on top of slender stalks, spurred, pubescent internally. Upper lip erect, 2-lobed, and 5-6mm long. Lower lip 8mm long, 1.3cm broad, glabrous, and 3lobed. Lobes to 3mm long, 1mm broad (in flower), linear-oblong, acute, green, glandular pubescent.

Seed Fruit

Fruits are capsules 3mm long and broad, many seeded, and glabrous.

Where Found

Dry, sandy, or rocky soil, abandoned fields, roadsides, open ground, glades, bluffs, prairies, and railroads.

Growth Habit

upright and nonwoody

Thorns or Spines

not present

Approximate Flower Diameter

Varies:

pencil,

dime

Dominant Flower Color

Varies:

white,

blue,

purple

Flower Symmetry

bilateral symmetry

Leaf Hairs

no hairs

Leaf Shape

Varies:

oval,

spatulate

Leaf Arrangement

Varies:

alternate,

opposite,

whorled

Leaf Margin

entire

Stem Hairs

no hairs

Stem Cross Section

round or oval

Milky Sap

not present

Root Structure

Varies:

fibrous,

taproot

Life Cycle

biennial

Ochrea

not present

Plant Type

Herb