This name is a synonym of Verbena litoralis Kunth.
The record derives from WCSP
(data supplied on 2012-03-26)
which reports it as a synonym (record 456033) with original publication details: Phytologia 16: 341 1968.
This name record (from WCSP) 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 Verbena sedula in version 1 of The Plant List.