Latin name: Cardamine hirsuta

Family:  Brassicaceae (or Cruciferae), Mustard family

Common name: This weed has a tremendous variety of common names, most relating to the way seed propel from the silique (seed pods).  The most used common name is bittercress, others include: pepperweed, shotweed, snapweed, ad infinitum.  Snapweed is the name of choice in British Columbia.

bittercress thumb
Life cycle:  winter annual;  Most prolific from late fall through early spring.  This weed is most problematic in propagation and overwintering.  Despite being a winter annual, bittercress will germinate and grow throughout the year due to the cool environment provided by daily overhead irrigation.
bc in liners
Habit:  Plants form a small mounded clump generally 4 to 8 inches tall and wide.  However, during warm summer months, bittercress generally grow much smaller.  Often, many seedlings germinate in a small area so that they appear as a large, dense mat.
foliage thumb
Foliage:  Each leaf generally contains 4 to 8 leaflets arranged alternately along the rachis.
bc flower
Flower:  Flowers occur in racemes.  Each flower has 4 white petals, generally 3 to 5 mm in diameter.
bc seedpod
Seed or seed pods:  Seed pods of bittercress are known as siliques, in fact, seed pods of all plants in the mustard family are considered siliques.  Siliques are a dry, two-sided, dehiscent fruit.
seedling thumbs
Cotyledon or seedling:  Cotyledons are round, and first true leaves are often simple and club-shaped (same general shape as leaflets on older foliage).
bc root
Roots:  Taproot

Bittercress and aphids:  As if bittercress weren't bad enough by itself, it also is a refuge for aphids.

Control: Evaluate 2003 herbicide trials conducted at Oregon State University.

Control: View 2004 granular herbicide trials for controlling this and other common container weed species.

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