Acmispon prostratus, synonyms Lotus nuttallianus and Syrmatium prostratum, is a species of legume native to California and northwestern Mexico.

It is a rare plant of the highly developed coastline in and around the city of San Diego, where threatened populations are known at Mission Bay,[4] the Silver Strand and Imperial Beach.

[5] This is an annual herb lined with leaves made up of oval leaflets one half to one centimeter long.

The inflorescence bears 3 to 8 red and yellow flowers each about a centimeter in length.

The fruit is a slender, curved legume pod containing usually 2 small beanlike seeds.