Rhizomatous, perennial herb, with plants attached to substrate. Rhizome with clusters of branches and basal leaves; cauline leaves ± erect; petiole not inflated. Primary bract 1, subtending the inflorescence. Inflorescence terminal, racemose, appearing spike-like, erect, few–many-flowered, with flowers usually crowded. Perianth lobes 0.5–0.8 cm long; ovary 3-locular, but only 1 loculus fertile with a single pendulous ovule. Infructescence remaining erect. Capsule single-chambered and achene-like, enclosed by hardened perianth base; seed (not seen in Australia) obloid or reniform.
5 species, in the Americas; 1 species frequently cultivated as a garden ornamental and occasionally naturalised in Australia.