The Poaceae are one of the largest families of flowering plants with about 500 genera and 8,000 species. Rhynchelytrum repens is an annual grass native to South Africa and is found throughout many counties in Florida. It was introduced as a forage species, but lacks the nutritional qualities of other species. Natal grass prefers dry conditions and is found in waste lands and perennial crop fields. The Florida Exotic Pest Plant Council lists natal grass as a Category I invasive.
Natal grass possesses branching culms that root at the nodes. These are able to reach 20 to 40 inches in height. The leaves are linear and 8 to 12 inches in length and grow from erect clumps. The flowers are borne in panicles 4 to 8 inches long, and are purple to pink in color with reddish hairs that turn gray with age. Although natal grass will perenniate, is primarily propagated by seeds, which are readily windborne.
Natal grass displaces native vegetation and prevents those species from regenerating. It is a primary invader of abandoned crop fields and unimproved pastures and prevents the natural succession of native species such as Andropogon and desirable forbs.
Do not allow seed setting to occur.
Remove all plants in the landscape.
Typically natal grass reseeds and resprouts vigorously following fire and quickly invades disturbed areas. In several areas in south Florida, natal grass has invaded scrub habitat following fire. Mowing will not provide control.
There are no known biological control agents for natal grass.
Spot treatments of glyphosate at 1-2% solution with surfactant will provide good control. Apply prior to flowering and seed set. Imazapyr will provide good control but is non-selective and will persist for several months in the soil. Preliminary research suggests imazapic (Plateau) may provide good control.