The leaves of hyacinth bean are pinnately divided, each consisting of three large leaflets. These egg-shaped leaflets measure 3-6 inches (7.6-15.2 cm) in length. The upper surface of each leaflet is smooth, while the underside is shorthaired. The leaflets have a distinctive oval shape that tapers toward the tip. The veins are prominently visible, providing a structured appearance. The overall texture of the leaves combines a glossy upper surface with a slightly roughened underside, making them easily identifiable.

The flowers of hyacinth bean are fragrant and form in elongated clusters. They have a pea-shaped structure and come in various colors, including white, pink, and purple. The petals are typically arranged in a bilateral symmetry, characteristic of the pea family. Each flower measures about 1-2 inches (2.5-5 cm) in length. Blooming predominantly occurs during the warmer months. The scent is pleasant and sweet, making the flowers an attractive feature for both pollinators and garden enthusiasts.

The stems of hyacinth bean are robust and can range from trailing to upright, extending to about 10-20 feet (3-6 meters) in length. They are notably purplish in color and covered with fine hairs, giving them a slightly rough texture. The stems exhibit a strong, sturdy aspect while being flexible enough to support the plant’s sprawling or climbing growth habit. Branching is irregular, enhancing the plant’s spread and support from the ground or surrounding structures.

The fruit of hyacinth bean showcases smooth, flat, pointed seedpods, ranging from 2 to 4 inches (5 to 10 cm) in length. These pods may exhibit diverse seed colors including white, cream, pale brown, dark brown, red, black, or a mottled pattern, varying by cultivar. The seeds, typically 2 to 4 per pod, are oblong-falcate, straight or slightly curved, and flattened. Select cultivars feature fleshy, thick-skinned pods without fiber. Pods can be septate, with internal partitions, or non-septate, depending on the variety.