Canna Bicapsularis is a shrub growing to 3.5 m tall. The leaves are 2.5–9 cm long, pinnate, with six to eight leaflets; the leaflets are 1.6–4.5 cm long and 1.1–2.3 cm broad. The flowers are produced a few together on short racemes, the individual flowers yellow, 12–16 mm long. The inflorescence is a raceme, or some arrangement or racemes.
The stamens may be as few as 4, but usually, there are 10. When 10, they occur in 3 sets. The 3 adaxial stamens are staminode. The 4 medial stamens are smaller than the 3 abaxial stamens. The anthers are basifixed and open by two terminal pores or short slits. The gynoecium is often deflected laterally to the right or left. This makes the flower asymmetric, but the perianth and the androecium may be asymmetrical as well. The fruit is a pod, indehiscent or tardily dehiscent.