Little-leaf Tick-trefoil is a perennial herb species of the pea or legume family (Fabaceae). It has erect stems from 0.4 to 1.0 meters tall, with long, spreading hairs. The clover-like leaves are compound, divided into 3 leaflets, and on petioles 2 to 10 mm long (and also spreading-hairy). The leaflets are 1.5 to 2.5 cm long, ovate-oblong to oval, blunt, and range from sparsely hairy to nearly glabrous. The flowers have the familiar "winged" shape of the pea family, and are 4-5 mm long (Gleason and Cronquist 1991). Their color may range from nearly purple to nearly white. The fruit separate into seeds covered with tiny, hooked hairs, well-dispersed by human socks and pant-legs.

Stems with both leaves and flowers are needed to identify this species.

Desmodium marilandicum has essentially glabrous leaves, and its petioles equal the lateral leaflets (1.2-2.7 cm long), while D. ciliare has pubescent leaves with the terminal leaflet longer than the petiole.