Colt's-foot, Tussilago farfara

Life Cycle

Perennial.

Propagation

Reproducing by rhizomes and by seed.

Stems

There are two types of stems, Flowering stems that are 5-50cm high, gray-woolly, with numerous short (1-1.5cm) grayish to dark purplish bracts. Each stem bearing a single flower head. There are also short, non-flowering stems producing normal leaves which begin to emerge as the flower heads reach maturity.

Leaves

Leaves on long, erect petioles, broadly heart-shaped, usually 7.5-13cm long by 10-20cm wide, occasionally much larger if in very fertile soil. The leaves are bright to dark green to bluish-green and hairless on the upper surface, white woolly on the undersurface, and palmately veined (main veins branching from the tip of the petiole). Leaf margins are inwardly scalloped to variously and irregularly toothed, the tips of the teeth often purplish.

Flowers and Fruit

Flower heads at first cylindric, expanding to 3.5cm wide when fully open; involucre same colour as bracts on stem, 8-15mm long; ray florets bright yellow, numerous, narrow (about 1mm wide), slightly longer than the involucre, and much longer than the pappus; disc flowers in centre of head, yellow, short and rounded; seeds produced only by ray florets, disc florets sterile; flower heads maturing in late spring to early summer, resembling dandelion heads but their pappus (parachute) is much finer and denser. Flowers from March to June.

Habitat

Colt's-foot was introduced from Europe and has been naturalized in forests, fields, disturbed and waste places and along roads, rivers, lakes, ravines and drainage ditches in urban and rural areas throughout southern and eastern Ontario.

Distinguishing Features

In its flowering stage, Colt's-foot can be distinguished from Dandelion by its several to many purplish bracts on the flowering stem. After flowering, the vegetative plant can be distinguished from young plants of Burdock by its perennial rhizome system and its broadly heart-shaped leaves being mostly palmately veined.

Legislation

Noxious under the Ontario Weed Control Act.


Figure #1.

B. Vegetative Stage: short stem with 3 leaves in midsummer.


Figure #10.


Figure #2.

A. Flowering stage: portion of a rhizome producing a shoot with several leafless stems and bright yellow flower heads emerging in early spring.


Figure #3.

Flowering stage of Colt's foot taken during mid April in Ontario, Canada.


Figure #4.

(d) narrow ray florets (e) disc florets in centre of head


Figure #5.

Flowering stem of Colt's foot with numerous purplish bracts.


Figure #6.


Figure #7.

(a) bracts


Figure #8.

Vegetative stage of Colt's foot.


Figure #9.

Leaf profile of Colt's foot.