Pectocarya heterocarpa

I've only seen this species at the Mohawk Dunes in southwestern Arizona, east of Yuma, where it forms small mats in the interdunes. It's apparently most common in southern California.

Single flowering stem at Mohawk Dunes, 2/27/05.

Wider view of the plant at Mohawk Dunes, 2/27/05.

Two nutlets at Mohawk Dunes, 2/27/05. These plants typically have four nutlets, two that look like this and two with larger hooked bristles around the margins, more like Pectocarya recurvata. Sometimes, however, two of the nutlets will fail to develop, as in this plant.