The attractive small, deep crimson-pink flowers are produced in early summer. Each has five sepals, with a corolla of five fused petals, and ten stamens fused to the corolla. They are pollinated by bumble bees and solitary bees. Each mature capsule contains about 180 seeds.
In the wild the plant may vary in height from 15–90 cm (6–35 in). New shoots arise from dormant buds on buried rhizomes. This process is stimulated by fire. The narrow evergreen leaves, pale on the underside, have a tendency to emerge from the stem in groups of three. A peculiarity of the plant is that clusters of leaves usually terminate the woody stem, for the flowers grow in whorls or in clusters below the stem apex.