Perennial herb, rhizome sprawling underground, robust; stem erect, much-branched, 30-100 cm tall, entire plant greenish, slightly hairy or densely pubescent, branches usually quadrangular. Leaves alternate or in whorls of three, lanceolate or broadly lanceolate, 4-6 (-10) cm long, 8-15 mm wide, apex obtuse or shortly acute, base rounded or cordate, sometimes slightly clasping the stem, entire, without petiole.

The flowers are arranged in small umbel inflorescences, clustered together. Due to the extremely short pedicels and rachis, the floral branches resemble a large spike-like inflorescence. The bracts are broadly lanceolate to triangular-ovate, measuring 5-12 mm in length. The calyx tube is 5-8 mm long, with 12 longitudinal ridges, slightly covered in coarse hairs, and the lobes are 6, triangular. The appendages are needle-like, erect, and 1.5-2 mm long. There are 6 petals, purple or light purple, lanceolate-oblong, with cuneate base, 7-8 mm long, attached to the upper part of the calyx tube, with short claws and slightly wrinkled. There are 12 stamens, 6 long and 6 short, extending beyond the calyx tube. The ovary has 2 chambers, with a stylus of varying lengths. The capsule is oblate.