Muraltia heisteria is an erect shrub of 1,5 m, often with several solitary stems standing out loosely. The leaves are sessile, lanceolate, hard in texture and tapering to sharp spiny tips that offer a prickly reception. Leaf margins may be hairy.

The five sepals are identical, forming a small calyx. Many of the small purple flowers are usually scattered along the stems, growing from upper leaf axils from winter to summer (Manning, 2007; www.plantzafrica.com).