The leaves of golden trumpet are leathery, glossy, and evergreen, arranged in distinctive whorls of four along the stems. They are simple and oblong-lanceolate in shape, measuring up to 6.3 inches (16 cm) long and 2.4 inches (6 cm) wide. These leaves have a robust, leathery texture and a vibrant green color. Each leaf typically reaches about 2.5 inches (6.5 cm) in length and 1.5 inches (4 cm) in width. The veining pattern is prominent, contributing to their characteristic texture and appearance.

The flowers of golden trumpet are tubular and bright yellow, clustered at the ends of branches from summer to fall. Each flower measures up to 3 1/2 inches (8.9 cm) and is held in groups of 12 on short branches or in the leaf axils. The yellow, funnel-shaped flowers are borne in axillary cymes, with sepals that are ovate to narrowly ovate. The flower corolla is five-lobed and spreading, showcasing a striking and vibrant yellow hue.

The stem of golden trumpet can twine up to 19 feet (5.8 meters) or more, showcasing a woody and twining texture. It contains a distinctive milky sap that is noticeable upon cutting or breaking. The stems are robust and flexible, facilitating their twining habit, and they typically exhibit a branching pattern that supports vigorous growth. The diameter of the stem can vary but is generally thick enough to provide structural support for the climbing nature of the plant.

The fruit of golden trumpet is a spiny capsule with a rough texture, typically forming upon pollination. These capsules exhibit a green to brownish shade, transitioning as they mature, and are known for their distinctive prickly exterior. Upon ripening, the capsules forcefully dehisce (split open), revealing seeds that are aerodynamically equipped with wings for propagation. Each seed is delicately attached within the pod, allowing for wind-assisted dispersal. The size of these pods is usually around 2 to 3 inches (5 to 7.6 cm) in length, and they contain multiple seeds that play a crucial role in the plant's reproduction.