Sulphur cinquefoil (Potentilla recta)
Erect, long-lived perennial 0.3 to 0.8 meters (1-3 feet) tall. Older plants often form a ring-shaped clump as old roots die in the center and new shoots grow on the outside edges. Introduced from Eurasia.
• Pale yellow flower with 5 petals.
• Long, stiff hairs perpendicular to stem.
• Relatively few leaves at plant base.
• Underside of leaf is green, not silver.
• Palmate leaves.
Unpalatable to grazing animals due to high tannin content.
Although primarily a seed producer, simply
eliminating seed production is not very effective in reducing or eliminating sulphur cinquefoil infestations. Hand-pulling is effective on small infestations provided the entire root is removed. Selective herbicide is also effective.
Pale yellow flowers, 1.3 to 2.5 cm in diameter, five heart-shaped petals; bright yellow centers. Contain 25 to 30 stamens. Found on top of stems.
Leaves and Stems:
A rosette on long-stalked leaves develops first and withers before flowering. Stems and leaves are covered with long, coarse, shiny hairs at right angles. Stem leaves are alternate, green on the underside, and composed of 5 to 7 leaflets with toothed margins. Leaflets appear like marijuana leaves (palmately compound).
Oval shaped dark brown seeds covered with net-like ridges.
Reproduction and Dispersal:
By seed and vegetatively. Most seeds fall near parent plant and disperse greater distances with water, soil movement, human activities and animals. Seeds survive three years or longer.
Woody tap root may have several spreading roots but no rhizomes.
Sulphur cinquefoil is one of 3 introduced cinquefoils found in BC. In disturbed areas it forms dense monocultures which exclude native vegetation. It is unpalatable to livestock.
Disturbed areas, grasslands, open forests, shrubby areas, roadsides and fields. Can invade healthy plant communities but does not tolerate full shade. Associated with knapweed infestations.