Abstract:
Amaranthus palmeri is native to Mexico and the south-eastern parts of the USA,
and is reported as alien in subtropical regions of the Old World. Previous records
from Africa were from the northern parts of the continent. This species was first
found in South Africa in March 2018 with further records in different regions of the
country as well as in northern Botswana in March 2020. We consider it as naturalized
weed which invades both ruderal and segetal plant communities. Mechanical control
of A. palmeri plants may be effective to minimize its spreading, because at the
flowering stage these tend to be taller compared to other amaranths. Those species
of the genus alien in Africa are discussed in terms of their distribution and possible
invasive status, particularly A. dubius and A. standleyanus.
