Smooth witherod features 4-inch long (approximately 10 cm) leaves that are glossy and dark green in color. The leaves are typically elliptical to oval in shape, with a smooth, leathery texture. The vein pattern on the leaves is pinnate, with a central midrib from which smaller veins extend outward. In the fall, the leaves may turn a striking reddish-purple, adding seasonal interest. These distinctive characteristics aid in the identification and appreciation of smooth witherod.

The flowers of smooth witherod are borne in flat-topped clusters, typically blooming from April to May. They feature creamy white petals arranged symmetrically, forming elegant, small, star-shaped blossoms. Each bloom measures approximately 0.25 inches (0.6 cm) in diameter, contributing to large, dense, and striking inflorescences. These clusters can span up to 4-5 inches (10-12.7 cm) across. The flowers emit a subtle, pleasant fragrance, attracting pollinators. Their clean, white color and uniform petal arrangement make the flowers easily recognizable.

The stem of smooth witherod features slender, reddish-brown, and shiny surfaces. It is characterized by its valvate buds, which are slender, scruffy pinkish-brown, and can grow up to 1/2 inch (1.27 cm) long. The texture is smooth and glossy, providing a notable contrast to its pinkish-brown buds. These defining traits make the stem easily recognizable and distinct.

The fruit of smooth witherod emerges as an enticing display, presenting a kaleidoscope of colors within each cluster. Initially, fruits blush a light pink, maturing through deep pink hues to reach a rich blue, ultimately darkening to purplish-black. This chromatic parade is not sequential but simultaneous, giving the clusters a multicolored palette. Each berry-like fruit is spheroid, with a slightly acidic taste that is nonetheless suitable for consumption. They make their appearance from late summer through fall, specifically August to October, adding a vibrant touch to the landscape. While regarded as edible, the fruits' culinary appeal is primarily due to their visual investment rather than gastronomic.