Cardamine douglassii Britton

Purple Cress

Cardamine_douglassii_plant.jpg
STATS

Native
CC = 9
CW = -3
MOC = 12

© DETenaglia

Family - Brassicaceae

Stems - To +40cm tall, erect, herbaceous, terete, hispidulous (mainly in the basal half), green, purplish at the base, simple to 1-2 branched in the apical half, from a short knotty rhizome.

Cardamine_douglassii_stem.jpg

© DETenaglia

Leaves - Alternate, petiolate below, becoming sessile above. Basal leaves on petioles to +8cm long. Petioles glabrous to hipidulous, flattened. Blades reniform to broadly ovate, glabrous, with wavy margins, +5cm long and broad. Cauline leaves becoming sessile or short petiolate, few (1-5), ovate to lanceolate, with a few coarse teeth, glabrous, light green below (abaxially), deep dull green above, with sparse ciliolate margins or not.

Cardamine_douglassii_leaves.jpg

© DETenaglia

Inflorescence - Terminal raceme, compact in flower, quickly elongating in fruit to +15cm long. Axis mostly glabrous. Pedicels ascending, to 2.5cm in fruit, glabrous.

Cardamine_douglassii_inflorescence.jpg

© DETenaglia

Flowers - Flowers not seen. Siliques to 3cm long, 2cm broad, glabrous, with a beak to 4mm long, 2-valved, with a small constriction between the seeds.

Cardamine_douglassii_calyx.jpg Calyx.

© DETenaglia

Cardamine_douglassii_flower.jpg Flower close-up.

© DETenaglia

Cardamine_douglassii_fruit.jpg Developing fruit.

© DETenaglia

Flowering - March - April.

Habitat - Low or swampy woodlands.

Origin - Native to U.S.

Other info. - This attractive species can be found mainly in the northern half of Missouri in a handful of counties. The plant can be identified by its reniform basal leaf blades, few, sessile or nearly sessile cauline leaves, and big flowers. The flowers are typically purple but the plants photographed in Columbia, MO., had white flowers.

Photographs taken off the MKT Trail, Columbia, MO., 4-15-04.