Small terrestrial to 25 cm tall. Leaf heart-shaped, to 4 cm long, to 2.5 cm wide, often held above the ground. Flowers 3-20, to 5 mm wide, purplish; autumn to winter. Sepals similar in length, dorsal wider than laterals. Petals smaller than sepals, pointing backwards. Labellum heart-shaped to elliptic, concave at base, warty near tip.
A. pusillus D.L. Jones is similar to A. exsertus and may sometimes be grown under that name. It has generally smaller flowers in a more congested raceme.