The balsa tree is a tall, deciduous tree that is fast-growing and can reach between 30 and 50 metres in height. Buttress roots grow above the ground and the base of its trunk and help to stabilize the tree on the forest floor.
Its deciduous leaves naturally fall at a specific time of the year. The leaves are simple, alternate, and heart-shaped (cordate) or divided into three or five shallow lobes (palmately lobed). They grow up to 40 centimetres long on a petiole of equal length.
The flowers are large, growing between 12 and 15 centimetres. They have five sepals (floral bracts resembling petals) and five white or cream petals, that are partially fused and create a tubular shape.
The fruit is a woody capsule 25 cm long and 2.5 cm wide. It opens into 5 valves to release large numbers of tiny black seeds bearing long silky filaments.