Alpine Enchanter's-nightshade

The leaves are opposite, ovate, 2–6 cm (0.8–2.4 in) and coarsely dentate. The 1.5–4 cm (0.6–1.6 in) petioles have a wing beneath. The flowers and fruits are clustered near the top of the fruiting raceme; each raceme bears 15 or less white or pink flowers in mid-May through early September. Each flower has two white to light pink petals 1–1.5 mm (0.04–0.06 in) long with two lobes. The two white sepals are 1–2 mm (0.04–0.08 in) long. The fruit is a small bur with one seed. C. alpina can reproduce vegetatively and via stolons.

Circaea alpina is generally found in forests or near streams from sea level to 3,000 metres (10,000 ft). In North America, is distributed throughout all of Canada. On the east coast of the US it can be found from Maine to North Carolina, and on the west coast, from Alaska to California. It is also established in most non-coastal states, excluding parts of the midwest and southeast regions. In Eurasia, the range of C. alpina spans from Northern Europe, south to Albania and Bulgaria, and east to Korea and Japan. C. alpina prefers a moist, upland habitat.