Perennials, (20–) 30–80 cm tall. Rhizome horizontal, creeping, long, branched, with internodes up 1.5 cm long, pale brownish; sterile shoots sometimes present. Stem erect, 1.5–4 mm in diam.; cataphylls 1–2, lax, later disappearing. Cauline leaves 2–4, usually 6–15 cm long, 1.0–1.5 mm in diam., unitubular, perfectly and prominently septate; auricles scarious to pale brownish, subacute to obtuse, c. 2.0–3.5 mm long. Stems, sheaths and leaves strongly longitudinally striate to sulcate (in transverse section with protuberances formed by epidermal cells irregularly superposed). Lower bract leaf-like, usually to 2 cm, much shorter than inflorescence. Inflorescence lax, anthelate, compound to decompound, of (2–) 7–20 (–50) semiglobose to globose dark brown (5–) 8–30 (–35)-flowered heads. Tepals unequal; inner tepals 2.8–3.8 mm long, narrowly lanceolate to lanceolate, gradually acuminate, cuspidate; outer 2.5–3.5 mm long, acute or mucronate, slightly deflexed at apex, greenish to stramineous-brown proximally, dark castaneous-brown apically; midrib very prominent; margins very narrow, scarious. Stamens 6; anthers 0.9–1.4 mm long, 1.5–2 (–3) times as long as c. 0.5 mm filaments; style to c. 0.3 mm long; stigmas 1.0–1.5 mm long. Capsule 3.5–4.5 mm long, exceeding perianth, unilocular, acutely trigonous, narrowly oblong-ovoid, tapering to a 0.7 mm rostrum, brownish, shiny. Seeds narrowly ovoid, (0.4–) 0.45–0.55 × c. 0.2–0.3 mm, pale brown, reticulate; appendages absent.
Leaves distinctly 20–30-sulcate/striate; anthers 1.0–1.4 mm long, 1.5–2 (–3) times as long as filaments; tepals greenish, or greenish at base and otherwise castaneous, or entirely castaneous; Seeds without appendages, often apiculate with visible tips to c. 0.1 mm long.
Known from SW Europe and the Mediterranean region. 12: COR, FRA, POR, SPA. 13: GRC, ITA, TUE. 20: ALG, MOR. 21: CNY. Wet meadows, subjected to mowing or not, on gley soils; sometimes in temporarily inundated places. Map 328.
12. FRANCE: Charente-Inférieure, Marais d'Anais, 29 Jun 1879, J.Foucaud (W). PORTUGAL: Faro, Jun 1887, A.Moller (COI); Setubal, Convento de S. Paulo, Aug 1900, A.Luisier (COI); Vila Viçosa, Herdade da Vigária, 10 May 1947, A.Fernandes & F.Sousa (COI). SPAIN: Albacete, El Vallejo, 25 Jun 1935, G.Albo (MA19349); Burgos, Miranda de Ebro, Jul 1934, T.M.Losa (MAF30229); Cádiz, Puerto de Santa María, 13 Jun 1970, E.F.Galiano, F.González Bernáldez & B.Valdés (SEV); Cuenca, Solán de Cabras, 12 Aug 1942, A.Caballero (MA19416); Huelva, entre Almonte y El Rocío, 25 May 1967, E.F.Galiano, V.H.Heywood & B.Valdés (SEV). 20. ALGERIA: Alger, L.C.Trabut s.n. (BRNU). MOROCCO: Tanger, Djebel Kebir, 25 Apr 1912, C.-J.M.Pitard 1362 (P).
Wet meadows, subjected to mowing or not, on gley soils; sometimes in temporarily inundated places.
Plants from Turkey and Greece have a longer capsule and shorter anthers than those from the western Mediterranean.