Astragalus lemmonii, the Lemmon' milkvetch, is a rare plant of eastern California. It is a member of the bean family, the Leguminosae (a. k. a. Fabaceae), and specifically a member of the subfamily Papilionoideae (a. k. a. Faboideae). The genus Astragalus is a large genus within this family; members of this genus are known as milkvetches or locoweeds. Close relatives of this particular species include Astragalus peckii and Astragalus lentiformis. The plant is a perennial plant. It has a fleshy to woody taproot, loosely matted to open and widely branched, herbage green but sparsely strigose, with basifixed hairs. Its several stems are slender and radiates from a superficial root-crown, prostrate to procumbent, herbaceous to the base, 10-50 cm, very sparsely strigose, floriferous from near the base. The stipules submembranous, semi- or fully amplexicaul but free, 2-5 mm. The leaves measures 1-4½ cm. Leaflets are 7-15, narrowly elliptic, lanceolate to oblong to oblanceolate; tips acute, subacute, or exceptionally emarginate; sparingly appressed-pubescent, 2-11 mm. The terminal leaflet is generally much broader than the subfiliform rachis. Inflorescence. The inflorescences are several and are often paired in the axils. These are distal, often 2 or 3 in one axil, one raceme of each pair usually developing much sooner than the other. The peduncles are slender, filiform, incurved-ascending at anthesis, mostly 1-2 cm long (much shorter than the leaves). Several (2-13) flowers are clustered at the ends of the peduncles. These flowers are ascending in subcapitate racemes.