Herbs creeping, glabrous or slightly tomentose. Leaves opposite, margin entire. Flowers perfect, densely clustered in heads. Heads terminal or axillary, globose or terete. Bracts papery; bracteoles keeled, without distal crest. Tepals 5, with short claw at base. Stamens 5; filaments subulate, connate into a cup at base, lateral appendages absent, pseudostaminodes absent; anthers 1-loculed. Ovary ovoid, compressed; style very short; stigma 2-parted; ovule 1, pendulous. Seeds shiny, lenticular.
Flowers perfect, bracteate and bibracteolate, subsessile in spikes. Sepals 5, discrete or basally slightly connate, hypogynous, the outer 3 flat and broader, the inner 2 conduplicate and narrower. Stamens 5, the filaments flattened and united below to form a very shallow tube; pseudostaminodia absent; anthers 2-locellate, introrse, medially attached. Ovary ovoid to orbiculate, 1-locular, 1-ovulate; ovules on elongate flattened funicles; stigmata 2, on 1 short style, often erect at anthesis and recurving in fruit. Fruit an orbiculate indehiscent utricle; seeds cochleate-orbiculate, reddish brown. Prostrate or decumbent glabrous to pubes- cent herbaceous perennials. Leaves opposite, entire, often succulent, the sessile bases usually amplexicaul. Inflorescences of terminal and axillary pedunculate congested spikes or glomes often subtended by slightly reduced foliar leaves.