The leaves of swamp bay are lanceolate, measuring 2-8 inches (5-20 cm) in length and 1-2 inches (2.5-5 cm) in width. They have entire margins and feature a dark green, shiny upper surface. The underside is silvery-white with an orange tinge due to pubescence primarily along the midvein, providing a distinctive contrast. These characteristics are key for identification and exhibit a unique texture and coloration pattern important for distinguishing the species.

Swamp bay produces small, light yellow-green flowers that are approximately 0.2 inches (5 mm) in diameter. These flowers form in small clusters, known as inflorescences, located in the leaf axils. The petals are modestly arranged around a central structure, contributing to a subtle but distinct appearance. Blooming occurs from May to June, adding a delicate touch of color to its environment. The flowers, although not overly fragrant, play a crucial role in the plant's reproductive cycle.

The stem of swamp bay features densely rusty pubescent twigs, giving it a unique, textured appearance. The surface is covered in fine, reddish-brown hairs, which create a velvety texture. The stems are moderately thick, usually around 0.5 inches (1.27 cm) in diameter. They exhibit a consistent branching pattern, with new growth emerging densely from the nodes. This rusty pubescence is a distinctive characteristic, setting it apart from other species and aiding in its identification.

The fruit of swamp bay presents as a distinctive dark blue berry, elegantly poised on fuzzy, reddish stalks. Flourishing typically from September to October, each berry measures approximately 0.5 to 1 inch (1.2 to 2.5 cm) in diameter. The skin of the fruit is smooth with a waxy sheen, encapsulating a pulpy interior. Upon maturity, the berries may exhibit a slight purple hue, further complementing their dark blue exterior. This fruiting body is not only recognizable by its rich coloring but also by the contrasting reddish tones of the supporting stalks.