It is a small shrub with woolly-hairy branches, egg-shaped leaves, and crowded heads of hairy flowers with brown bracts.

Spyridium × ramosissimum is a shrub that typically grows to a height of 40–60 cm (16–24 in), its branches covered with woolly hairs.

Flowering occurs from August to October and the fruit is a capsule about 3 mm (0.12 in) long.

[2][3] This species was first formally described in 1922 by James Wales Claredon Audas who gave it the name Trymalium × ramosissimum in The Victorian Naturalist from specimens collected on Mount Difficult in the Grampians.

[2][6] Spyridium × ramosissimum is a hybrid between S. daltonii and S. parvifolium and is only known from the Grampians, where both parent species occur.