Purple cress

Cardamine is derived from the Greek kardamon, meaning cress. David Douglas (1798-1834) is the namesake for douglassii. He was a Scottish plant collector for the Royal Horticultural Society.

The soft flowers of Cardamine douglassii are pale purple to pink and sometimes nearly white. Each flower has 4 petals with 4 purplish sepals, numerous stamens and a single style.

The flowers look very similar to some of their relatives- Cardamine concatenata and Cardamine bulbosa. All are native to Arkansas, share similar habitats and may be found flowering at the same time. There are some tips to help differentiate all three in the 'Plant Description' section below.

Cardamine douglassii has a single stem which may have one or two branches at the top. The stem is hirsute and light green often with a purple tint, especially toward the base. Several leaves are usually present at the base of the plant. These basal leaves are oval with long petioles and typically green above and purple underneath. Stem leaves are alternate, and either sessile or clasping. The leaves become smaller and more narrow toward the top of the stem.

It's easy to differentiate Cardamine douglassii from Cardamine concatenata as the leaves are completely different. The leaves of Cardamine concatenata appear in whorls of 3 and are highly dissected and toothed. Take a look below.

Differentiating between Cardamine douglassii and Cardamine bulbosa is more challenging, requiring close attention to plant height, stem pubescence and color of the sepals. Here are a few tips that can be helpful to distinguish the two plants.

Cardamine douglassii:

• shorter plant, reaching about 12 inches (vs about 18 incues)
• hirsute stem (vs glabrous stem)
• flowers typically with pink or purple hue (vs white)
• sepals are purplish and hairy (vs green to yellow)

Information about the pollinators and insect visitors of Purple cress are limited. I've documented syrphid flies, various species of bees and one butterfly (Falcate orangetip) visiting the plants in our woodlands.

Purple cress is found in moist, mesic woodlands, in many cases near limestone. I frequently spot them growing beneath the deciduous trees, especially the large oaks.

Although Natureserve shows this plant as secure, in Arkansas it is listed as S1 meaning it is Critically Imperiled in the state.

In Arkansas it also has a very high Conservation value, 9 out of 10, meaning it has a strong fidelity to intact habitats.

Deer rarely feed on this plant. The leaves have a bitter taste. The deer much prefer to eat the mearby Mayapple leaves.