Melaleuca sieberi is a small tree with white, grey or brown papery bark which sometimes grows to a height of 20 m (70 ft) but more usually less than 10 m (30 ft).
Its leaves are arranged alternately, 4–15 mm (0.2–0.6 in) long, 0.8–4 mm (0.03–0.2 in) wide, narrow elliptic to lance-shaped and tapering to a sharp point.
The leaves are often  covered with short, soft hairs, especially when young.


The flowers are white or pinkish, arranged in spikes on the ends of branches which continue to grow after flowering.
The spikes contain 5 to 20 groups of flowers in threes, or sometimes individual flowers, and are up to 20 mm (0.8 in) in diameter and  20 mm (0.8 in) long.
The flower buds are woolly.
The stamens are arranged in five bundles around the flowers and each bundle contains 11 to 25 stamens.
Flowering occurs in the spring and is followed by fruit which are woody, cup-shaped capsules 3–4.5 mm (0.1–0.2 in) long in loose clusters.
Melaleuca sieberi is a small tree with white, grey or brown papery bark which sometimes grows to a height of 20 m (70 ft) but more usually less than 10 m (30 ft). Its leaves are arranged alternately, 4–15 mm (0.2–0.6 in) long, 0.8–4 mm (0.03–0.2 in) wide, narrow elliptic to lance-shaped and tapering to a sharp point. The leaves are often  covered with short, soft hairs, especially when young.

The flowers are white or pinkish, arranged in spikes on the ends of branches which continue to grow after flowering. The spikes contain 5 to 20 groups of flowers in threes, or sometimes individual flowers, and are up to 20 mm (0.8 in) in diameter and  20 mm (0.8 in) long. The flower buds are woolly. The stamens are arranged in five bundles around the flowers and each bundle contains 11 to 25 stamens. Flowering occurs in the spring and is followed by fruit which are woody, cup-shaped capsules 3–4.5 mm (0.1–0.2 in) long in loose clusters.
Melaleuca sieberi