Lepidium virginicum var. pubescens in Kyle Canyon near junction of 157 and 158, Spring Mountains, southern Nevada [Note: This image is misidentified. As the original uploader pointed out, it was different from the others in having sessile leaves. This is Lepidium campestre, a common relative, differing from L. virginicum in its sessile leaves and a much more pubescent inflorescence.]
(This one looks rather different from other L. virginicum photos I've examined, for instance in the way that the leaves are held close to the stem, but it's the closest match of the several species known from the Spring Mountains.)