Allium atrorubens grows from a reddish-brown bulb 1–1.5 cm (0.4–0.6 in) across. The stem is short and is surrounded by few coiled tubular leaves. Atop the stem is an inflorescence of up to 50 flowers. Each flower has six shiny, iridescent, sharply triangular tepals with dark midveins. The tepals are usually magenta to maroon but are lighter pink or white occasionally. Each flower is about 1 cm (0.4 in) wide.
^Cronquist, A.J., A. H. Holmgren, N. H. Holmgren & Reveal. 1977. Vascular Plants of the Intermountain West, U.S.A. 6: 1–584. In A.J. Cronquist, A. H. Holmgren, N. H. Holmgren, J. L. Reveal & P. K. Holmgren (eds.) Intermountain Flora. Hafner Pub. Co., New York.