Sambucus racemosa is a deciduous shrub or tree, capable of reaching heights of 30 feet. The branched stems are hairless and woody lower down, smooth, green and finely hairy higher up. Leaves are compound, divided into five or seven narrow, fine-toothed leaflets, often somewhat folded up along the prominent midvein. Leaflet tips are pointed. Leaves may have a light covering of stiff hairs, most likely along the veins.
The inflorescence is a relatively compact, terminal, branched, somewhat elongated cluster - about as tall as wide - containing numerous small, cream-colored, five-petaled flowers, each centered on five stamens and a lobed stigma. The petals may be angled back, below the plane. Fruits are berry-like drupes, colored bright red (
var racemosa) or dark purple (
var melanocarpa).
The similar
sambucus cerulea has flat-topped rather than racemic flower clusters, and glaucous, bluish-black fruits.