Cardamine flexuosa | Easy Wildflowers

There are two closely related species of Bittercress. They look superficially very similar and share the same properties. There is not a great deal of difference between the two species and many people will be content to know them simply as Bittercress.

They are both members of the Mustard family, they are both edible and generally they are both regarded as a weed by gardeners.

Hairy Bittercress, (Cardamine hirsuta) is a small winter annual, the leaves are green during the winter months and it flowers in early spring.

The flowers are small (2-4 mm across) with four white petals.

The plant is characterised by the seed capsules that emerge from the centre of the flowers.

Reddish at first they turn green as they ripen. The seeds are arranged inside like peas in a pod and the pods burst explosively throwing the seeds far from the plant. The seeds germinate in the autumn and winter as green leaves.

It is characteristic of the Hairy Bittercress that the seed pods often rise well above the flowers.

The stem of Hairy Bittercress is smooth and not hairy.

Stem leaves are long and thin. There are not many of them.

Most of the leaves are around the base of the plant and these are rounder than the stem leaves.

The definitive difference between Hairy and Wavy Bittercress is the stamen count.

Hairy Bittercress has four stamens.

Wavy Bittercress, (Cardamine flexuosa) has six stamens, a small difference but it is indicative of species.

Wavy Bittercress is a biennial or perennial. It has the same characteristic seed capsules as it’s relative but they tend to be less conspicuous and seldom grow above the topmost flowers.

It has fewer basal leaves.

Unlike it’s “Hairy” relative the stem of Wavy Bittercress is hairy.

These differences can be quite subtle, the only real way to be sure of the species is to count the stamens.

These two species of Bittercress are both native to the UK and they can hybridize, making any distinction very difficult. They can also hybridize with another close relative, the beautiful Cardamine pratensis. (I would call that “getting lucky”)