This looks like Imperata cylindrica, cottonwool grass or in Afrikaans, donsgras (down grass). Imperata cylindrica is a perennial with strong rhizomes.  It does not branch and grows to 1,2 m, typically in poorly drained soils.  The habitat in South Africa is widespread in the north eastern parts of the country, particularly Kwazulu-Natal, Mpumalanga, Limpopo and the eastern Free State.  Separated components of the habitat exist in the Western and Eastern Cape coastal areas.  It also grows throughout Swaziland and Lesotho and is found further to the north.  In Mozambique it is used as thatching (Van Oudtshoorn et al, 1991).