Whitlowgrass

Whitlowgrass (Brassicaceae family):

Draba verna L.

EPPO code:

ERPVE

Other names:

Spring whitlowgrass

Species information

Lifecycle:

Annual, winter annual.

Propagation:

Reproduces by seed.

Emergence:

Whitlowgrass emerges in the fall or early spring and usually completes its life cycle by mid-May.

Habitat:

Although it is most often found in cereal crops, whitlowgrass has also been found in soybean and corn crops. Recent surveys found it to be most prominent in south-central Ontario.

Competitiveness:

Whitlowgrass does not impact yield, even in cereal crops where it is often found.

Identification clues

Seedlings

Cotyledons:

Very small (1 mm), round to club shaped with a short petiole, rapidly masked by leaves.

First leaves:

The plant’s first leaves appear as a basal rosette of oblong leaves that are covered in small, fine hairs.

Mature leaves:

Similar to first leaves.

Mature plant

Stem:

Whitlowgrass does not have stem leaves. The bolting, wiry stem that rises from the basal rosette does, however, produce several small, white flowers.

Flowers:

The flowers of whitlowgrass are extremely small and have a yellow centre. The flower has four white petals that are so deeply lobed as to give it the appearance of having eight petals instead.

Seeds:

Seedpods are flat, football shaped and about 3 mm long.

Roots:

Fibrous

Often mistaken for

I know it's not Shepherd’s purse because whitlowgrass flowers much earlier than shepherd’s purse, has a much smaller basal rosette (about the size of a dime) and the seedpods are football shaped in comparison to the heart-shaped seedpods of shepherd’s purse.

I know it's not Canada fleabane because whitlowgrass has narrower basal leaf blades that are much hairier than those of Canada fleabane.