A herbaceous perennial, 400–700 mm high, with a rhizome that is creeping at times. The stem is erect and sparsely branched. The leaves are clustered at the base of the stem, they are oblong to wedge-shaped, linear to spoon-shaped or linear, 90–300 mm long and 6–17 mm broad. There are also often 1 to 3 cauline pairs of leaves (leaves growing on the upper part of the stem) that are smaller than the basal leaves, linear, 20–140 mm long and 1–7 mm broad, and usually much shorter than the internodes.

The flowers are magenta to rose-pink, red, or rarely white, in a terminal cymose panicle, with pedicels that are 10–30 mm long. The bracts are oblong to ovate, 10–0 mm long, a little cucullate (curled up) at base, with an acute apex. The calyx tube is very short, about 1–2 mm long, with lobes linear to lanceolate,  5–7 × 1.5–2.0 mm, acute at the apex, with a hyaline (delicate membranous and colourless) margin. The corolla is about 20 mm long, with a tube 7–10 mm long, and lobes 13 × 6 mm, with an acute apex. Stamens are inserted about 1.5 mm inside the throat of the corolla, with filaments that are 3.5–4.0 mm long and anthers that are slightly spirally twisted and 5 mm long. The ovary is 7–8 × 1.5–2.0 mm long, and narrows into a style of about 10 mm long, ending in a stigma that is bilobed and 20 mm long. After fertilization, it produces narrowly ovoid capsules about 9–12 × 3–5 mm, with seeds of about 0.35 mm in diameter. The time of flowering is summer.