Abundant in shade under Mexican palo verde tree in sandy soil with Logfilia filaginoides, Bromus sp., other grasses, Erodium cicutarium. Nutlet more or less winged with teeth with bristles, toothed along entire edge. Fruit straight to slightly curving throughout.

Keyed using the Jepson eFlora. Nutlet scar concave, nutlet with adaxial ridge. Lower cauline leaves alternate and upper alternate, taprooted. All parts of stem, leaves, margins and midveins green. Nutlet with cross ribs with flat wide areas between.

iNat says A. retrorsa is now synonymous with A. m. menziesii but according to the Jepson eFlora A. retrorsa is a valid species? I keyed this to retrorsa based on a number of factors including the basal layer of short recurved hairs on the stem (very distinct in later photographs).