Annual or winter annual.
Reproducing by seed and by horizontally spreading leafy stems which root at the nodes.
Chickweed stems are prostrate, spreading and much-branched, 5-50cm long, soft and bright green with swollen nodes (Figure 1). The stems are generally smooth except for a single, narrow lengthwise line (about 1mm, wide) of fine white hair on one side of each branch, this line of hair alternating from one side of the branch to the other on successive internodes (Figure 2). Chickweed stems will root from nodes that touch the ground which allow the plant to spread by forming dense, matted patches.
Flowers are small, white, produced at tips of stems and in angles between branches. The petals are white, shorter than the 3-4mm with long green sepals. Each of the 5 petals is 2-lobed so the flower may appear to have 10 tiny petals (Figure 3). The seedpod is somewhat egg-shaped, about as long as or slightly longer than the sepals with the tip splitting into 6 tiny teeth and releasing the reddish-brown somewhat spherical seeds which are about 1.2mm in diameter. It may start blooming in early spring and produce flowers and seeds throughout the growing season.
Chickweed occurs throughout Ontario in a wide variety of habitats and soil textures. It is one of the most common weeds in lawns but is equally at home in gardens, cultivated fields, pastures, waste areas and even under deciduous forests.
It is distinguished from similar plants by its bright green colour, its ovate-pointed leaves, and the single lengthwise line of fine white hair on one side of the stem but switching sides above and below each node (Figure 2).
Chickweed. A. Plant. B. Section of stem with a single flower between the pair of branches and showing narrow lengthwise lines of hair on alternate sides of the stem. C. Seedling, top view. D. Seedling, side view. E. Young plant.
A 2-leaf chickweed plant with oblong cotyledons.
A 4-leaf chickweed plant with oblong cotyledons.
Fine white hair on one side of chickweed stem.
Leaf of chickweed that is oval with a pointed tip.
Flower of chickweed with the 5, 2-lobed white petals.
Flowers and seedpods of chickweed.
Mature chickweed in a field during May in Ontario