Claytonia sarmentosa is a small, loosely matted herb in the purslane family (Portulacaceae) with outsize pink flowers, found in moist, lush areas such as meadows and snowbeds on tundra in the alpine and subalpine zones. Its multiple flowering stems reach 1-15 cm high, arising from subterranean, filiform (threadlike) rhizomes. Basal leaves are long-petioled, elliptic or lanceolate. Stem leaves are opposite, sessile and ovate. The flowers are arranged in a raceme. There are five petals, pink or white with pink veins, 2 sepals, and both stamens and styles. Fruits are a small green capsule which splits open to release the seeds. Claytonia sarmentosa can be distinguished from Claytonia scammaniana species by its broader leaves and its habitat—Claytonia sarmentosa occurs in meadows and lush sites whereas C. scammaniana is primarily a plant of barren, loose scree slopes.
This species flowers in early summer in Denali.
Claytonia sarmentosa is monoecious with bisexual flowers. Flowers are insect pollinated, most likely by flies, bees and wasps. It readily reproduces asexually through rhizomes and stolons. Seeds are flung out when capsules split open. Seeds have a prominent elaiosome—a lipid-rich food-packet that attracts ants, who carry the seed to their nest, remove the elaiosome, and leave the seed intact to germinate.
Claytonia sarmentosa is an amphi-Beringian endemic species, occurring in Russia, Alaska, Yukon and northern British Columbia. Claytonia sarmentosa is widespread in the hills and mountains of Alaska except absent or very rare in the southeast panhandle. In Denali, C. sarmentosa is common and widespread in suitable habitat in the mountains, on both sides of the Alaska Range crest.
Claytonia sarmentosa is an alpine species that is found from 543 m to 1573 m with an average plot slope of 1121 m. It occurs more commonly on north facing slopes and prefers moderate to steep sites, with an average plot slope of 15 degrees.