Cardamine species, The Bittercress (Hairy and Wavy)

Hairy Bittercress, (Cardamine hirsuta)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.

Hairy Bittercress, (Cardamine hirsuta)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.

Hairy Bittercress, (Cardamine hirsuta)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.

Hairy Bittercress, (Cardamine hirsuta)

Hairy Bittercress, (Cardamine hirsuta)It is characteristic of the Hairy Bittercress that the seed pods often rise well above the flowers.

Hairy Bittercress, (Cardamine hirsuta)The stem of Hairy Bittercress is smooth and not hairy.

Hairy Bittercress, (Cardamine hirsuta)Stem leaves are long and thin. There are not many of them.

Hairy Bittercress, (Cardamine hirsuta)Most of the leaves are around the base of the plant and these are rounder than the stem leaves.

Hairy Bittercress, (Cardamine hirsuta)The definitive difference between Hairy and Wavy Bittercress is the stamen count.

Hairy Bittercress has four stamens.

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

Wavy Bittercress, (Cardamine flexuosa)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.

Wavy Bittercress, (Cardamine flexuosa)It has fewer basal leaves.

Wavy Bittercress, (Cardamine flexuosa)Unlike it’s “Hairy” relative the stem of Wavy Bittercress is hairy.

Wavy Bittercress, (Cardamine flexuosa)These differences can be quite subtle, the only real way to be sure of the species is to count the stamens.

Wavy Bittercress, (Cardamine flexuosa) Wavy Bittercress, (Cardamine flexuosa)   Wavy Bittercress, (Cardamine flexuosa)   Wavy Bittercress, (Cardamine flexuosa)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”)

Cuckooflower (Cardamine pratensis)Taxonomy:

Kingdom: Plantae

Order: Brassicales

Family: Brassicaceae

Genus: Cardamine

Species: Cardamine hirsuta
Species: Cardamine flexuosa

Wavy Bittercress (Cardamine flexuosa)Back to White Wildflowers

Back to the start

Advertisements

One thought on “Cardamine species, The Bittercress (Hairy and Wavy)”

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s