Tree to 10 m tall; bark rough to c. 4 cm diam. branches, firm to corky, hardly furrowed, grey over red-brown. Crown green, stems on coppice growth and branchlets of canopy conspicuously yellow. Juvenile leaves opposite at first, sessile, green, glossy, to 6.5 cm long, 1.2 cm wide, tapering at base, by 1–1.5 m tall becoming alternate, petiolate, broadly lanceolate to falcate; adult leaves lanceolate or falcate, to 20 cm long, 2 cm wide, glossy, green. Inflorescences axillary, unbranched; peduncles to 0.5 cm long, 7-flowered; buds shortly pedicellate, fusiform or ovoid, scar present; operculum conical. Fruit shortly pedicellate, cupular to hemispherical, to 0.6 cm long, 0.7 cm diam.; disc ascending; valves 3 or 4, exserted; seed brown to blackish, flattened-ellipsoid, reticulate, lacunose, hilum ventral. Flowers ?Oct.
This species may be confused with Eucalyptus viminalis subsp. cygnetensis, which grows nearby. The early juvenile leaves in particular may be distinguished by the tapering leaf-bases. Intermediate leaves in E. splendens become alternate and petiolate sooner than in E. viminalis subsp. cygnetensis. Fruit are like E. viminalis subsp. cygnetensis. The correct systematic placement of this taxon is as yet uncertain.
