Mariscus grantii C.B.Clarke Cyperus vorsteri is a sedge of the family Cyperaceae native to KwaZulu-Natal in South Africa.

[2] The rhizomatous perennial sedge typically grows to a height of 1.5 metres (4.9 ft) and has a robust tufted habit.

[4] The species was originally described as Mariscus grantii by the botanist Charles Baron Clarke in 1898 as part of the Thiselton-Dyer work Cyperaceae.

[1][6] It was subsequently reclassified into the genus Cyperus in 1994 by Karen Wilson in the work New taxa and combinations in the family Cyperaceae in eastern Australia published in the journal Telopea.

[4] It has been introduced in Western Australia where it is found along streams and creeks in Kalamunda in the outer metropolitan region of Perth where it grows in sandy-clay soils.