Twenty-six plant species, representing 16 families, were collected
between January and March 1997 and are listed in
Table 1. Voucher specimens of each species were
processed according to standard procedures and deposited
in the herbarium of the National Museum in Bloemfontein
(NMB). Although it may not necessarily be true for the areas
where the plants were collected, 15 of these species (Table
1) are listed as problem plants in agriculture (Wells et al.
1986). The reasons vary, but primarily concern competition
for space, light, water and nutrients, that they smother crops
and that their seeds or fruits are regarded as contaminants.
The woody species are mainly listed as problem plants
because of their ability to replace preferred vegetation
(mainly grazing) and obstruct the movement of machinery