Banksia epimicta is a prostrate, spreading shrub with its stems more or less on the ground and that forms a lignotuber. It has crowded, pinnatifid leaves that are linear in outline,  long and  wide on a petiole up to  long, with between ten and thirty-five sharply-pointed, curved teeth on each side. The flowers are borne on a down-turned head containing between forty-five and seventy pungent-smelling flowers in each head.
Banksia epimicta is a low-growing, spreading shrub with its stems almost touching the ground and forming a root system. It has densely packed, deeply cut leaves that are narrow in shape, long and wide on a stem up to  long, with between ten and thirty-five sharply-pointed, curved teeth on each side. The flowers are borne on an inverted cluster containing between forty-five and seventy pungent-smelling flowers in each cluster.