Capnoides sempervirens aka Rock Harlequin

Capnoides sempervirens, or rock harlequin, belongs to the poppy family. It grows as an annual or biennial wildflower. Its native range spans Alaska, much of Canada, and northern and eastern parts of the United States. It reaches south through the Blue Ridge Mountains into Georgia. It grows in rocky woods and on burned or disturbed ground. Wild plants also grow on cliffs, granite outcrops, and in rock cracks.

Plants form upright clumps, growing 1–4 feet [0.30–1.22 metres] tall. They spread 1–2 feet [0.30–0.61 metres] wide and grow fast. Slender stems branch above the base and have no hairs. Their green surface has a gray or blue cast. A waxy coat covers both stems and leaves. The soft, blue-green leaves look like fern fronds. Each leaf is pinnately divided, then split again into narrow parts. Lower leaves have stalks, while upper leaves tend to lack them. A low rosette forms first and may last through winter. Plants that follow this two-year cycle send up flowering stems next season.

Flowers can appear from spring through fall, depending on location. Appalachian plants bloom before those in western states. Racemes near the stem tops hold three to ten hanging flowers. Each pink tube has a yellow tip and one spur. Four petals make up each flower, which has six stamens. The outer petals join to form the tube. The smaller inner petals meet at their tips. Slim, upright capsules follow the blooms, each holding about 25 seeds. The dry capsules split when ripe and release their seeds.

Grow rock harlequin in full sun or part shade. It suits dry soil that drains well, including poor, gravelly ground. It prefers acid soil but also accepts neutral soil. Cold winters and cool summers suit it best. The listed USDA hardiness range is zones 2–6. Growers can raise plants from seed or divide them. Its low care needs make it useful in rock gardens. Cottage gardens, woodland settings, and meadows offer other uses.

The flowers draw bees and butterflies to the garden. Bumblebees and skipper butterflies feed on their nectar. Mass plantings show off both the flowers and fine foliage. No major insect or disease problems are reported. Plants can become weedy, so that trait matters when choosing a site. Native Americans used the plant to treat pain. The supplied evidence does not establish its safety as food or medicine.