[citation needed] It is native to the dry mountain slopes and deserts of southern California, mainly the deserts of eastern San Diego County, where it grows in scrub and woodland habitat.

It is a small bushy perennial herb spreading with mostly naked, slender stems.

The inflorescence is generally made up of one or two yellow to reddish pealike flowers each under a centimeter long.

[citation needed] The species was first described in 1889 by Charles Russell Orcutt as Hosackia haydonii.

It was subsequently transferred to Lotus by Greene in 1890, to Syrmatium by August Brand in 1898 and independently by Amos Arthur Heller in 1913, and to Acmispon by Luc Brouillet in 2008.