The photo is of a hairy bittercress flowering stem.

Hairy bittercress – Cardamine hirsuta

Cardamine hirsuta L.

Brassicaceae (Mustard family)

MI Status

Non-native

Life cycle

Rapidly growing winter or summer annual.

Leaves

Round cotyledons on long petioles are followed by heart- to kidney-shaped first two true leaves. Subsequent leaves are compound with two to eight alternately arranged leaflets and larger terminal leaflet. Leaflet margins are shallowly toothed to lobed. Mostly hairy leaves initially develop from a basal rosette, followed by a few smaller, narrow stem leaves. Basal leaves are persistent through maturity.

Stems

Mostly erect, smooth, angled stems branch mainly at the base. Stems are less than 12 inches tall.

Flowers and fruit

Very small, white flowers with four petals are arranged in terminal clusters. Fruit are very narrow, about 1-inch-long, flattened, upward-pointing capsules that explosively eject numerous small seeds.

Reproduction

Seeds. Multiple generations may be produced in a single year.

Similar weeds

Smallflowered bittercress (Cardamine parviflora L.) differs by having up to six leaflet pairs and basal leaves that are not present at maturity.

 

More information and control options

The photo is a close up of a hairy bittercress flower.  The flowers are small with four white petals.
Hairy bittercress flower
The photo is of a hairy bittercress flowering stem
Hairy bittercress flowering stem
The photo is of a hairy bittercress rosette with hairy leaves.  The leaf margins are shallowly toothed to lobed.
Hairy bittercress rosette
The photo is of a hairy bittercress seedling. It has round cotyledons on long petioles.  The two first true leaves are heart- to- kidney shaped.
Hairy bittercress seedling
The photo is of hairy bittercress fruit.  The fruit is narrow, inch long, flattened capsules.
Hairy bittercress fruit
The photo is of a hairy bittercress leaf.  The leaves are compound with 2 to 8 alternately arranged leaflets and a larger terminal leaflet.
Hairy bittercress leaf

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