Pink (Caryophyllaceae family):
Stellaria media (L.) Vill.
EPPO code:
STEME
Other names:
Common chickweed

Species information

Lifecycle:
Annual or winter annual.
Propagation:
Reproduces by seed.
Emergence:
Typically two main flushes of germination in the spring and in the autumn.
Habitat:
Chickweed is found throughout Ontario in a wide range of habitats and in many cultivated crops.
Competitiveness:
Since chickweed typically occurs at high plant densities its impact on yield can be quite significant. It is also an alternate host for other crop pests, namely wireworm and soybean cyst nematode.

Identification clues

Seedling

Cotyledons:
Oblong to elongated with pointed apex.
First leaves:
Chickweeds first leaves are oval, and have opposite orientation, entire margins and a pointed tip. Leaf stalks are hairy.
Mature leaves:
Similar to its younger leaves.

Mature plant

Stem:
Prostrate, spreading or sometimes erect, depending on the environment, chickweed’s stem has a narrow, lengthwise strip of fine hairs that alternate side after each node.
Flowers:
Chickweed has very small flowers with five white, two-lobed petals that give it the appearance of 10 petals.
Fruit:
The fruit of chickweed appears as an oval capsule that contains several light brown to reddish seeds, which are flat and circular with a notch.
Roots:
Taproot

Often mistaken for

I know it's not Grass-leaved stitchwort because the stem of grass-leaved stitchwort lacks the lengthwise fine hairs of chickweed. In comparison to chickweed, which has sparse hairs, grass-leaved stitchwort is hairless.

I know it's not Scarlet pimpernel because the leaves of scarlet pimpernel have several small purple spots, while chickweed leaves lack any markings at all. While chickweed flowers are white flowers, the flowers of scarlet pimpernel are salmon-coloured.

I know it's not Mouse-eared chickweed because chickweed is hairless except for a single line of hairs along the stem while mouse-eared chickweed is hairy all over.

A small seedling with opposite leaves
A small seedling with opposite leaves.
Rosette-looking, mature, flowering plant in mid-June
Rosette-looking, mature, flowering plant in mid-June.
The stems contain a line of short hairs that alternate from one side to another following each internodes
The stems contain a line of short hairs that alternate from one side to another following each internodes.
A flower consisting of five white and deeply lobed petals
A flower consisting of five white and deeply lobed petals.
Flowering chickweed in a winter wheat field during early May
Flowering chickweed in a winter wheat field during early May.