The leaves of american bladdernut are distinct trifoliate, each consisting of three ovate leaflets measuring 2 to 4 inches (5 to 10 cm) in length. The terminal leaflet is stalked with a petiolule up to 1 inch (2.5 cm) long, while the lateral leaflets are nearly sessile. Leaflets are dark green and hairless on the upper surface, and light green with fine hairs on the lower surface. They have a rounded to wedge-shaped base and taper to a slender tip. In autumn, they turn a vibrant yellow.

The flowers of american bladdernut are greenish-white and bell-shaped, arranged in nodding panicles. Blooming in April and May, these drooping clusters emerge from the axils of compound leaves. Each flower measures about 1/3 inch (8.5 mm) long and 1/4 inch (6 mm) across, featuring 5 outer sepals, 5 inner petals, several stamens, and a pistil. The flowers initially appear white, with sepals turning light green or dull pink over time. The slender pedicels are slightly longer than the flowers.

The young stems of american bladdernut are notably smooth and red-brown in color. They exhibit a consistent texture that transitions smoothly into matured growth. The stems are relatively slender, averaging around 0.5 inches (1.3 cm) in diameter. They possess a branching pattern that is dichotomous, where each branch emerges directly opposite each other. This distinctive coloration and texture aid in the easy identification of american bladdernut.

The fruit of american bladdernut is distinguished by its inflated, bladder-like seed capsules, each measuring 1 to 2 inches (2.5 to 5 cm) in length. These papery, egg-shaped structures present a unique obovoid or ovoid form with three angular lobes, transitioning from a vibrant green in summer to a light brown hue in fall. Within each segmented chamber of the capsule, a solitary seed resides, capable of producing a rattling sound when mature. These capsules are typically available from August to October and are notable for persisting on the plant into early winter.