This name is a synonym of Acalypha brachiata Krauss.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50235982) with original publication details: Fl. Trop. Afr. 6(1): 889 1912.
This name record (from Tropicos) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Acalypha senensis in version 1 of The Plant List.