It is a small, straggling, erect to low-lying shrub sometimes with spiny branches, and has cylindrical leaves and loose clusters of white, bell-shaped flowers that turn pink to red as they age.

Cryptandra tomentosa is a small, straggling, erect to low-lying shrub that typically grows to a height of 25–30 cm (9.8–11.8 in), its branchlets sometimes ending in a spine.

The floral tube is broadly bell-shaped, 1.5–2.5 mm (0.059–0.098 in) long and white, ageing to pink or red, the sepals about the same length as the floral tube, and the petals about 0.5 mm (0.020 in) long.

[2][3][4] Cryptandra tomentosa was formally described in 1838 by botanist John Lindley in Thomas Livingstone Mitchell's Three Expeditions into the interior of Eastern Australia.

[7] Prickly cryptandra grows in heath and woodland west of Port Phillip Bay in Victoria and in south-eastern South Australia, including on Kangaroo Island.