Gouania hillebrandii is an erect to sprawling shrub form, forming clumps with stems that are 2–20 decimeters long and covered in densely pale to brown pilose. Its leaves are simple and alternate, with broadly to narrowly elliptic blades, occasionally obovate–elliptic or lanceolate, measuring 1.4–6.5 cm in length and 0.8–4 cm in width. The leaves have short-acuminate, acute, or obtuse to rounded apices, often mucronate to emarginate, and bases ranging from rounded to broadly cuneate. While the upper surfaces of the leaves become smooth (glabrate) over time, the lower surfaces range from sparsely to densely covered with appressed pilose hairs. The leaves are chartaceous to somewhat coriaceous and have entire margins with 3–5 conspicuous veins spreading from the base. Petioles, 0.4–4 cm long, are densely white pilose, and the stipules are linear-lanceolate, 2–8 mm long, showing varying degrees of persistence. The flowers occur in axillary cymes, 15–50 mm long, emitting a strong sweet fragrance. It is andromonoecious, having both bisexual (perfect) and staminate flowers, with the latter positioned laterally to the central perfect ones. The calyx comprises five sepals, each 1.5–2.5 mm long and densely pilose. The corolla includes five white petals, approximately 0.6–1.5 mm long, enveloping the stamens. There are five stamens with filaments adnate to the petal bases. The inferior ovary is 3(4)-celled, abortive in staminate flowers, with one ovule per cell. The fruit is 4–11 mm long, densely covered with appressed white pubescent hairs, and uniquely 3–3-winged, with wings 1.5–3.5 mm wide that extend the length of the fruit but taper toward the base. Seeds are brown, glossy, and narrowly ellipsoid, measuring 3–4 mm long. It is found in pastures and on slopes at elevations ranging between 244-518 meters.