Gramineae

Robies Cocksfoot, Kropaargras.

Chloridoideae; Chlorideae. There is only one species in the genus.

There is only one species, occurring in South Africa and Pakistan. Its habitat is high altitude grassland in open habitats, often in alluvial soil. Occurs on sandy soil on riverbanks, rocky outcrops or mountain slopes, at altitudes higher than 1200 m. Its abundance ranges from infrequent to locally common. Cultivated on a small scale in South Africa.

A perennial rhizomatous and tufted grass that grows to a height of 300-900 mm tall. Leaf blades are up to 130 mm long and 1 mm (but can be up to 5mm) wide, and are curled when dry. Culms branch freely. Inflorescence 100-300 mm long. Spikes more than 4, stout, 10-40 mm long, not spreading far from the central axis, more or less their own length apart. Semi-procumbent and forming dense stands when grazed.

It is probably the best grazing grass in its area of distribution, but is easily overgrazed due to its high palatability. Particularly valuable for sheep. It has already disappeared in many parts of its former area of distribution.

Chromosome base number, x = 10.

C₄ photosynthetic pathway.

None reported and considered to be non-toxic.

Found in mountainous regions with low to moderate rainfall (300-700 mm per annum) and a temperate climate. It is a climax species that decreases during overgrazing. In South Africa, Tetrachne dregei is often found growing with Themeda triandra, Festuca spp. (F. costata, F. scabra, F. caprina), Pentaschistis spp., Merxmuellera disticha, Elionurus muticus, Heteropogon contortus and Eragrostis spp. (E. chloromelas, E. capensis and E. curvula).

Requires sandy soil.

Tetrachne dregei is cultivated on a small scale in South Africa. It transplants well, but has difficulty in re-establishing itself from seed, especially on hard ground. Seed therefore should be planted in holes in the ground, or amongst gravel. In the wild, germination is rare (Zacharias 1990) but is most successful in gravely and stony places, or where there is a certain amount of litter on the surface of the soil, or, if in the open, where there is a wash of sand over the hard surface of the subsoil.

Flowers from November to March.

None known.

Tetrachne dregei is extremely slow growing from seed, possibly taking more than ten years to reach full maturity (Zacharias 1990). However it establishes well from transplantation.

Acocks, J.P.H. 1988. Veld types of South Africa (3rd edn.). Mem. Bot. Surv. S. Afr. No 28. Government printer, Pretoria.

Gibbs-Russell, G.E., Watson, L., Koekemoer, M., Smook, L. Barker, N.P., Anderson, H.M., Dallwitz, M.J. 1989. Grasses of southern Africa. Memoirs of the Botanical Survey of South Africa, No. 58, National Botanical Institute, Pretoria.

Low, A.B. & Rebelo, A.G. (eds.) 1996. Vegetation of South Africa, Lesotho and Swaziland. Companion to the vegetation map of South Africa, Lesotho and Swaziland. Dept. of Environmental Affairs and Tourism, Pretoria.

Van Wyk, E. & Van Oudtshoorn, F. 1999. Guide to grasses of southern Africa. Briza Publications, Arcadia, South Africa.

Zacharias, P.J.K. 1990. Acocks' Notes: key grasses of South Africa. Grassland Society of Southern Africa, Howick.