Scirpus thermalis Trabut in Battandier & Trabut, Flore de l'Algérie, Monocotyledones: 99. 1895. Scirpus litoralis Schrader subsp. thermalis (Trabut) Murbeck, Lunds Univ. Årskrift, N.F., Avd. 2, 18(3):18. 1922; Scirpus subulatus Vahl, Enum. Pl. 2: 286. 1806; Schoenoplectus litoralis subsp. subulatus (Vahl) T. Koyama in Dassanayaka & Fosberg, Fl. Ceylon 5: 157. 1985; Scirpus pectinatus Roxb., Fl. Ind., 1: 218. 1820; Haines & Lye, Sedges and rushes E. Africa: Fig. 66. 1983.

Stem 3-6 mm diam., basal parts terete, distal obtusely trigonous, sides convex. Blades to c. 15 cm, sometimes (in water) to 30 cm, c. 5 mm wide, keel and margins scabrous, apex long attenuate, acute. Inflorescence 20-70 mm; lowest bract mostly c. equalling inflorescence; to secondary multiple spikes with 3-8 peduncled, solitary spikes.

Fl. Per.: (February-) March - July.

Type: Algeria: "Ruisseau d'écoulement de la fontaine chaude, Ain-Salahin, Biskra".

In shallow water; in ditches and rivers; Distribution: Africa, Madagascar, Italy, Arabia, from Iran to Pakistan, India, Thailand, Australia, New Guinea, Micronesia; reported from Japan (Okinawa).

Status of Scirpus thermalis Trabut in Battandier & Trabut (l.c.) is unclear. Protologue of S. thermalis gives name in italics and it is followed by description in smaller print. Perhaps, only a new variety was intended as understood by Maire in Flore de l'Afrique du Nord 4: 67 (1957). Whatever the case, as pointed out by Townsend (Kew Bulletin 15: 415-417, 1962), the two taxa are, for most part, allopatric and where they meet distinction is not always clear-cut. Thus, subspecific rank is appropriate.