Common sandweed (Athysanus pusillus) is one of those small white spring wildflowers that are difficult to see unless one is crawling on the ground. They are often just as difficult to identify.
Native to western United States and Canada, common sandweed has a simple, spindly stem or is sparingly branched from near the base. The alternate, lance-shaped leaves show toothed margins. The miniscule white flowers have four petals. The fruits are circular, flat, green and covered with prominent white hairs. Indeed, the entire plant is covered with hairs.
Common sandweed is a member of the mustard family. Other common names for this short-lived annual are anthysanus and dwarf anthysanus.
The genus Anthysanus is monotypic, that is, there is only one species in this genus. Pusillus, the species name comes from the Latin and means “very small”.
Common sandweed is found in a variety of moist habitats. This specimen was along the Pacific Crest Trail overlooking the Crystal Lake Fish Hatchery (Shasta County CA).