Related to A. lotoides but different in the non-silvery leaves, the sparser and more elongate spikes, the recurved calyx lobes and the more intensely yellow petals. It is not quite clear to which other species these two are most closely related, although a close affinity with A. tridentata, A. quinquefolia is possible.
A decumbent or procumbent shrublet with branches ascending only beneath the floral spikes; branches up to 0.4 m long but not rising more than 0.15(-0.2) m above the ground. Young branches tomentose-sericeous. Leaves trifoliolate, those of young long-shoots linear or narrowly (ob-)lanceolate, 7-12 x 0.2-2 mm, acute or obtuse, flexible, green, sparsely sericeous or glabrescent. Leaves of short-shoots much smaller, subglabrous, densely situated (hence the name 'heterophylla'). Inflorescence a ± sparse spike 40-80 mm long or more, its flowers at a distance of 5-10 mm. Bract lanceolate, 3-10 x 0.5-3 mm, pointed, weak, green, with sparse, half-spreading hairs. Pedicel very short. Bracteoles linear or narrowly lanceolate, as long as the bract but narrower. Calyx with long, straight hairs (in old herbarium specimens often brownish); lobes linear(-triangular),(2-)3.5-7 mm, green, ± recurved, with sparse long hairs. Petals light to clear yellow. Standard blade ovate, 5-7 x 4.5-5.5 mm, acute, tomentose on the back. Wing blades oblong, 4-6 x 2-2.5 mm, sericeous on lower-apical parts, with 2-3 rows of minute folds on upper-basal parts. Keel blades lunate, 3.5-4.5 x 2-2.5 mm, sericeous(-tomentose), upper margin slightly S-curved. Pistil pubescent on ovary and style base; ovules 5 or 6. Pod small, ovate, tomentose, slightly more than 3 x 1.5 mm. Ripe pods not seen.
Sprawling shrublet to 20 cm. Leaves 3-foliolate, leaflets linear-oblanceolate, flexible, subglabrous, leaves on short shoots smaller and crowded. Flowers scattered in spikes, pale yellow to yellow, wings and keel silky, calyx thinly and softly hairy, lobes linear, attenuate-recurved.
Du Toit's Kloof region (Worcester Division) in the south through the western divisions(Worcester, Tulbagh, Piketberg, Clanwilliam, Vanrhynsdorp and Calvinia Divisions) to the Nieuwoudtville region in the north.