13. ISOLEPIS R. Brown, Prodr. 221. 1810.
[Greek, isos, equal, similar, and lepis, a scale]
S. Galen Smith
Scirpus Linnaeus sect. Isolepis (R. Brown) Grisebach
Herbs, annual or perennial, cespitose, rhizomatous or not, smooth, glabrous. Culms terete. Leaves all basal; sheaths green to stramineous, sometimes reddish proximally; ligules absent; blades rudimentary to exceeding culms. Inflorescences terminal, sometimes pseudolateral, capitate or solitary spikelet; spikelets 1–3(–15); involucral bracts 1(–2), spreading to erect, like foliage leaf blades. Spikelets: scales 8–25, spirally arranged, each subtending flower. Flowers bisexual; perianth absent; stamens 1–3; styles linear, 2–3-fid, base persistent, sometimes slightly enlarged. Achenes biconvex or trigonous, papillose or longitudinally ribbed.
Species 69 (4 in the flora): worldwide in cool-tropical and temperate regions, especially Africa and Australia.
Isolepis is difficult to delimit on a worldwide basis and has been included in Scirpus in the broad sense. Data derived from embryologic, genetic, and other studies led in recent years to the acceptance of Isolepis as a distinct genus (J. J. Bruhl 1995; P. Goetghebeur 1998; A. M. Muasya et al. 2001).
SELECTED REFERENCES
Muasya, A. M. 1998. Systematics of the Genus Isolepis R. Br. (Cyperaceae). Ph.D. thesis. University of Reading. Muasya, A. M. and D. A. Simpson. 2002. A monograph of the genus Isolepis R. Br. (Cyperaceae). Kew Bull. 57: 257–362. Muasya, A. M., D. A. Simpson, M. W. Chase, and A. Culham. 2001. A phylogeny of Isolepis (Cyperaceae) inferred using plastid rbcL and trnL-F sequence data. Syst. Bot. 26: 342–353.
