The rigid stems of galium stellatum
are covered by short, rough hairs, and they branch readily, the branches spreading or ascending. The pointed, grey-green leaves are in whorls of four, at regular, closely-spaced intervals, and have a similar hair covering. Leaves taper smoothly to a sharp point.
The inflorescence is a leafy panicle, at the top of the branches, typically containing a dozen or more flowers. The small, star-shaped flowers have a white to greenish-yellow, four-lobed corolla, hairy on the underside, containing either stamens or a pistil. Fruits are small, paired nutlets, enclosed by many long, straight, white hairs.