Circaea alpina

The leaves are opposite, ovate, 2–6 cm and coarsely dentate. The 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 long with two lobes. The two white sepals are long. The fruit is a small bur with one seed. C. alpina can reproduce vegetatively and via stolons. ==Taxonomy==

Circaea alpina was given its scientific name by Carl Linnaeus in 1753. It is classified in the genus Circaea within the Onagraceae family. According to Plants of the World Online it has six accepted subspecies: • Circaea alpina subsp. alpina – Widespread in the northern hemisphere • Circaea alpina subsp. angustifolia – Native to China and Tibet • Circaea alpina subsp. caulescens – Native to Asia • Circaea alpina subsp. imaicola – Native to southern Asia • Circaea alpina subsp. micrantha – Northern Pakistan to Central China and northern Myanmar • Circaea alpina subsp. pacifica – Western North America Circaea alpina has synonyms of the species or one of its subspecies, 16 of which are species. ==Distribution==

In North America, Circaea alpina is distributed throughout all of Canada and North Carolina through Maine and New Mexico through Washington. In Eurasia, the range of C. alpina includes Northern Europe south to Albania and Bulgaria and east to Korea and Japan. C. alpina prefers a moist, upland habitat. It is generally found in forests or near streams from sea level to . ==Hybrids==

Circaea alpina will hybridize with Circaea lutetiana producing sterile offspring that persists in vegetative colonies. ==References==