Wild onion is a perennial, growing from a bulb, with the odor of onion or garlic. Flowers in umbels (the flowers all arising from the tip of the stalk) that are held erect at flowering (not drooping), each flower resembling a 6-pointed star with the petals spreading widely, pink (sometimes white), showy. Blooms July–November. Leaves basal, narrow, flat.
Similar species: Nodding wild onion (A. cernuum) is found in the same region and habitats. It is distinguished by its nodding (not erect) flowerheads and, especially, by its bell-shaped (not broadly spreading) flowers. It also tends to flower earlier in the season (June–September).