[2] Joseph Hooker and Thomas Thomson, the British botanists who first formally described the species, named it after the dense covering of hair (tomentosus in Latin) on its young branches, leaves and flowers.

The leaves are hairless and shiny on their upper surfaces and densely covered in fine hairs underneath.

Its inflorescences are composed of up to 1-2 flowers on a densely hairy rachis positioned opposite from leaves.

Each flower is born on a fleshy pedicel that is 11-22.5 by 1-2 millimeters and densely covered in fine yellow-brown hairs.

The yellow, lance-shaped outer petals are 16-34 by 7.5-18 millimeters with pointed tips and wavy margins when mature.

The fruit have a longitudinal ridge, their surface has a whitish waxy sheen and short brown hairs.

The stipes are attached to a woody pedicels that is 15-33.5 by 2.7-4.3 millimeters and densely covered in pale brown hairs.