Santalum haleakalae var. haleakalae is an evergreen small tree that can grow from 1 to 8 meters tall with either a single or multiple stems and demonstrates hemiparasitic behavior on the roots of other plants. This variety is notable for its ability to spread vegetatively through root sprouts when surface roots are exposed or damaged, sometimes forming small stands. The leaves are simple and opposite, with blades that are broadly ovate, elliptic, or orbicular, measuring (2.2–)2.9–5.1(–6.5) cm in length by (1.2–)1.8–3.1(–4.0) cm in width. These leaves have a thickly coriaceous texture, an acute or obtuse apex (rarely acuminate), and a cuneate base. They are more glaucous on the lower surface, with paler surfaces on the lower side and olive to dark green on the upper side. The margins are flat to slightly recurved, and the petioles range from (1.2–)2.0–7.4(–11.6) mm in length. The flowers are bisexual (perfect) and weakly fragrant, appearing in dense, terminal (rarely axillary) inflorescences. These reddish to cream-colored buds become deep pink to red flowers throughout or with white to pink interiors, longer than wide, presented in congested, terminal, compound cymes. The corolla is formed by 4 (rarely 5) petals, with a campanulate to cylindrical floral tube. The fruit of this variety is a drupe that turns black or purplish black at maturity, measuring 9–14 mm in length and adorned with a subapical receptacular ring. The seeds are muricate (studded) with a pointed beak on one end. It is found in subalpine and montane mesic forests between 1,800-2,700 meters.