Anemone richardsonii is a creeping herb with solitary yellow flowers found in streambanks, moist thickets and lush meadows that occurs from the lowlands into the alpine zone. Plants grow up to 5-20 cm tall from a slender rhizome. Plants will send up single, long-petioled leaves from the rhizome, and flowering stems with a pair of opposite leaves beneath the bud. Basal leaves are palmatelylobed, round in outline, with the margins toothed. Stem leaves are 3-cleft, toothed, and without petioles. Flowers have approximately six yellow tepals (looking like petals), which are hairy on the underside. The 25-55 yellow stamens surround a conic compound ovary, with many styles. After flowering, the plant matures to have a rounded head of many dry fruits (achenes). The achenes are hairless, with a long curved beak, which is also hooked at the apex. This is the only yellow-flowered anemone species in the Alaskan flora, and is also the only anemone with hooked, hairless achenes.
Yellow thimbleweed flowers early. This species is perennial.
Anemone richardsonii is monoecious, with bisexual flowers. Many species of Anemone are both self-fertile and out-crossed (Lindell 1998), others are strictly out-crossing (Douglas and Cruden 1994). Though A. richardsonii's pollination has not been studied, other species of the genus with similar flowers are bee-pollinated. The breeding system of yellow thimbleweed is unknown. After flowering, the plant matures to have a rounded head of many dry fruits (achenes). The achenes have a hooked beak, which aids in dispersal.
Yellow thimbleweed is an amphi-Beringian species that occurs across Canada and Alaska, reaching into Siberia to the west. In Denali, Anemone richardsonii occurs across the Park in suitable habitat, and is most common in the hills, mountains and major river floodplains.
Yellow thimbleweed has the widest range of elevations of the Anemones: 91 to 1753 m, peak frequency at 900-1100 meters. It is common everywhere but the steepest slopes (>28 degrees). It shows a slight preference for north-facing slopes.