4. Cyperus subg. Juncellus (Griseb.) C. B. Clarke
Cyperus sect. Juncellus Griseb., Fl. Brit. W. Ind.: 562. 1864. Juncellus (Griseb.) C.B. Clarke, in J.D. Hooker, Fl. Brit. India 6: 594. 1893; Acorellus Palla, in W.D. Koch, Syn. Fl. Germ. ed. 3,2: 2557. 1905.
Tufted perennials, rhizome short- or long-creeping. Leaf blades foliose or ± reduced. Inflorescence pseudo-lateral cluster of spikes. Stamens 3, stigmas 2. Nut positioned with flat side against spike rachis.
The subg. Juncellus is here restricted to contain C. laevigatus and related species with pseudolateral inflorescences; thus corresponding genus Acorellus Palla and not following the treatment by Clarke (l.c.) nor Kükenthal (in Engler, Pflanzenr. IV,20, Heft 101, 1936). Palla (l.c.) indicated that Acorellus would contain c. 7 spp., of which he, for Europe, named only three, namely A. pannonicus (Jacq.) Palla, A. laevigatus (L.) Palla and A. distachyos (All.) Palla. In this sense the subgenus occurs in an area from Central Asia and western India westwards through Africa to Americas south from southern U.S.A. The distribution of C. laevigatus s.l. is often given unprecisely as pantropical; it occurs in dry tropical areas, but extends, primarily along the coasts, from India to S. Europe, and further to southern Africa and from southern N. America south to Argentina and Chile.
In Fl. Iranica (Kukkonen 1998) an attempt was made to distinguish C. laevigatus L. (type: from South Africa) and C. distachyos All. (type: Italy, Piemonte) but this could not be made satisfactorily. In the area of Fl. of Pakistan the distinction is even more difficult to accomplish, and therefore the name C. laevigatus is applied here collectively. Some specimens from coastal area of Pakistan may be assigned to C. laevigatus, and similarly some inland specimens may represent C. distachyos, but the bulk of specimens would rather represent intermediate forms. In fact an intermediate species has been described from Spain as C. junciformis Cav. (Icon. & descr. pl. 3,1:2, tab. 204, fig. 1, 1795; = Acorellus distachyos x laevigatus, Palla, Allg. Bot. Zeitschr. 9: 166, 1903; = A. pallae Kneucker, Allg. Bot. Zeitschr. 13: 31, 1907; see also Clarke l.c.: 84, 1884). A comprehensive study of the complex is needed.