Tree to 20 m tall, rarely a mallee; bark rough over part or all of main trunk, black to dark grey, fibrous, shedding in ribbons. Juvenile leaves petiolate, alternate, usually ovate, to 13.5 cm long, 6.5 cm wide, dull, blue-green; adult leaves petiolate, alternate, lanceolate, rarely falcate, 6.5–16 cm long, 1–3.5 cm wide, concolorous, glossy, green; reticulation moderate, with numerous island oil glands and scattered intersectional oil glands. Inflorescences axillary, unbranched; peduncles flattened, to 4 cm long, 7–13-flowered; buds pedicellate, elongate, swollen at join, to 2.4 cm long, 0.8 cm diam., scar present; operculum horn-shaped, much longer than hypanthium; stamens erect; anthers versatile, dorsifixed, oblong; ovules in 4 vertical rows; flowers cream to pale lemon. Fruit pedicellate, rarely sessile, campanulate, to 1.4 cm long, 1.3 cm diam., disc level to descending; valves 4 or 5, usually exserted; seeds blackish-brown, ovoid to flattened-ovoid, with distinct shallow reticulum, hilum ventral. Flowers Nov.–May
Wim, VVP, VRiv, GipP, OtP, CVU, HSF. Native to West Australia. In Western Australia Eucalyptus occidentalis generally occurs in wet depressions. Occasionally spreading from planted trees in Victoria.
