Sub-category: Dogbane family
A trailing, viny subshrub, spreading along the ground and rooting along the stems to form large clonal colonies and occasionally scrambling up to 40 cm high but never twining or climbing. The leaves are evergreen, opposite, 2 to 4.5 cm long and 1 to 2.5 cm broad, glossy dark green with a leathery texture and an entire margin. The flowers are solitary in the leaf axils; they are violet-purple (pale purple or white in some cultivated selections), 2 to 3 cm diameter, with a five-lobed corolla. The fruit is a pair of follicles 2.5 cm, containing numerous seeds.
The species is commonly grown as a groundcover in landscaping in temperate gardens for its evergreen foliage. Blooms mainly from early spring to mid summer but with a few flowers still produced into the autumn.