Eucalyptus sideroxylon, commonly known as mugga ironbark, or red ironbark is a small to medium-sized tree that is endemic to eastern Australia. It has dark, deeply furrowed ironbark, lance-shaped adult leaves, flower buds in groups of seven, white, red, pink or creamy yellow flowers and cup-shaped to shortened spherical fruit.
Eucalyptus sideroxlylon is a tree that typically grows to a height of 25–35 m (82–115 ft) and forms a lignotuber. The bark is dark grey to black, deeply furrowed ironbark on the trunk and larger branches, smooth white to grey on the thinnest branches. Young plants and coppice regrowth have lance-shaped to oblong or linear leaves that are 30–110 mm (1.2–4.3 in) long and 5–35 mm (0.20–1.38 in) wide. Adult leaves are lance-shaped, the same shade of green on both sides, 50–140 mm (2.0–5.5 in) long and 10–40 mm (0.39–1.57 in) wide tapering to a petiole 5–25 mm (0.20–0.98 in) long. The flower buds are arranged in leaf axils on an unbranched peduncle 7–29 mm (0.28–1.14 in) long, the individual buds on pedicels 3–15 mm (0.12–0.59 in) long. Mature buds are oval or diamond-shaped, 6–15 mm (0.24–0.59 in) long and 4–6 mm (0.16–0.24 in) wide with a conical to beaked operculum. Flowering occurs from April to December and the flowers are white, red, pink or creamy yellow. The fruit is a woody cup-shaped to shortened spherical capsule 5–11 mm (0.20–0.43 in) long and 5–10 mm (0.20–0.39 in) wide with the valves below the level of the rim.[
