Two new African species of Acalypha (Euphorbiaceae subfamily Acalyphoideae) are described and illustrated. Acalypha guineensis from Guinea and Sierra Leone is most similar to A. manniana, from which it differs by its smaller size, shorter peduncles on the pistillate inflorescences, smaller pistillate bracts with shorter and fewer teeth that are broadly triangular rather than linear-triangular, and velutinous rather than setose ovaries. Acalypha cupricola, endemic to copper-rich soils in the southern Democratic Republic of the Congo, belongs to the same species group as A. clutioides, A. dikuluwensis, and A. fuscescens, but can be distinguished from all three by its greater stature and more densely pubescent leaves. This name previously was a nomen nudum, and we also review other invalid names published by Robyns with A. cupricola.