Chenopodium capitatum has an amphi-Atlantic distribution, occurring in Europe and across North America (but not in Asia). This species is widespread in North America, occurring coast to coast in both the lower 48 states and Canada (absent from southeastern and southern central U.S. states. In Alaska, C. capitatum occurs in the east-central portion of the state, north to the Porcupine River, south to the Anchorage area, and west to Denali. It is not common in Denali, where it has been found along the road corridor, west to near Wonder Lake and also along the Toklat River near the northern park boundary.
This plant is monoecious with bisexual flowers. The flowers of Chenopodium capitatum are wind-pollinated. The fleshy fruits are eaten by birds, dispersing the seeds.
Chenopodium capitatum is one of the few annual plants in the flora. It typically flowers in mid-summer.
Chenopodium capitatum is a tall annual plant in the goosefoot family (Chenopodiaceae) with hastate (arrow-shaped) leaves and bright red fleshy clusters at intervals up the stem in fruit. Plants grow up to 50 cm tall from a taproot, found in open soil and disturbed sites in Denali. Leaves are alternately arranged, 10 cm long, triangular-hastate, irregularly toothed and somewhat fleshy. Stems are erect, green and glabrous, branching or unbranched. Flowers are in dense globose clusters along the stem, lacking petals, some with 3-4 stamens others with 1 or none. The sepals become fleshy and bright red in maturity, covering the fruit and giving the impression of an aggregate berry. No other plant in Denali has hastate (arrow-shaped) leaves and round clusters of red fruit along the stem.