The 5-lobed calyx is bristly, yellow, hairy, and encloses the 4 seedlike nutlets. Each nutlet contains I seed and is usually referred to as a seed. The nutlets are grayish, somewhat eggshaped. They have a sharp ridge down the back, a slightly winged angle underneath, and are covered by grayish pebblelike bumps. May. It is relished by livestock when young, and in years of good winter moisture may form an important part of the spring forage on desert ranges.
Sheep are either immune or highly resistant to the poison.
The disease is common in the Pacific Northwest, but not in Arizona. This plant also may cause nitrate poisoning.