The color and form of the flowers are the best ways to identify astragalus preussii
; the lower, tubular portion (the calyx) is purple-red, while the upper petals are a much lighter pink-purple, becoming bluish when dry. The uppermost petal (the banner) is wider than the others and arches upwards. The plant often forms large clusters containing hundreds of flowers. Leaves have the familiar pinnate arrangement, with 5 to 25 leaflets. One more unusual identifying feature is the rather unpleasant smell, as the plant accumulates selenium when growing. The uncommon cutleri
variety has white flowers, and larger, fewer leaflets.