winter cress

not listed

NNA - Not applicable

SNA - Not applicable

not listed

FACU - Facultative upland

FAC - Facultative

FAC - Facultative

Winter cress is a 8″ to 32″ tall, erect, biennial or short-lived perennial forb that rises from a stout taproot. In it’s first year it forms a rosette of basal leaves up to 1′ across. In the second year it produces one or more flowering stalks. This is one of the first flowers to bloom in spring. It blooms a second time in late autumn.

The stems are erect, angled, and usually unbranched below the inflorescence. They are usually hairless but are sometimes sparsely covered near the base with unbranched, nonglandular hairs.

The leaves are alternate, dark green, hairless, and shiny on the upper surface. Basal leaves are up to 6″ long and 2″ wide and are attached to the stem with a ¾″ to 3″ long leaf stalk. They are divided into 1 to 4 pairs of small lateral lobes and a large terminal lobe. The lateral lobes are oblong, two to four times longer than broad with nearly straight sides or egg-shaped and attached at the narrow end. The terminal lobe is considerably larger, egg-shaped or nearly circular. The margins are wavy or bluntly toothed.

Lower stem leaves resemble the basal leaves but are progressively smaller as they ascend the stem. A pair of ear-like basal lobes clasp the main stem.

Upper stem leaves are egg-shaped or nearly circular and may be lobed, toothed, or entire. The margins are strongly wavy or bluntly toothed. They attach to the main stem without a stalk and sometimes clasp the stem at the base. They are not covered with a whitish, waxy coating (glaucous).

The inflorescence is a terminal, branched, elongated, crowded cluster.

The flowers have four yellow petals, are ½″ wide, and are stalked.

The fruit is an ascending or spreading, ½″ to 1½″ long, narrow, curved pod that is roundish in cross-section. The fruits develop below the inflorescence.

8″ to 32″

Yellow

Early winter cress (Barbarea verna) has basal leaves with 4 to 7 pairs of lateral lobes. It is an eastern and west coast species and does not occur in Minnesota.

Northern winter cress (Barbarea orthoceras) is a native species. The flowers are ¼″ wide. The flower stalk is club-like or bat-like in overall shape.

Moist. Fields, pastures, roadsides, and other disturbed sites.

April to June, September

This and other mustards (family Brassicaceae) produce chemical compounds when cells are damaged that are toxic to most animals, fungi, and bacteria.

Sources

2, 3, 4, 5, 7, 22, 28, 29, 30.

Native to Northern Africa, Asia and Europe. Introduced and naturalized in the United States.

Common

Four varieties have been described but these are not recognized by most authorities.

Plant

Inflorescence

Flowers

Basal Leaves

Lower Stem Leaves

Middle Stem Leaves

Upper Stem Leaves

Fruit

Location: Pine Bend Bluffs SNA