Two new annual species of Nemesia Vent, are described from southern Africa. N. williamsonii is characterized by bright orange flowers with an inflated yellow palate. It differs from the related N. maxii Hiern by having a spur that projects backwards, not downwards, and bracts that are lanceolate with a truncate base, not triangular or cordate. It is unusual for the genus in having dimorphic seeds.  N. williamsonii occurs almost exclusively in the Richtersveld. but has been collected in a few localities across the Orange River in southern Namibia. N. hemiptera is a delicate, wiry-stemmed annual with small white flowers. The flowers are characterized by a tiny nipple-like spur and a seed that is winged on onlv one side. N. hemiptera isendemic to the Kamiesberg from near Garies to Kamieskroon. Keywords: Kamiesberg, Namibia, Nemesia Vent., new species, Richtersveld, Scrophulariaceae. seed dimorphism, southern Africa.