This name is a synonym of Senna mexicana var. shaferi (Britton & P. Wilson) H.S. Irwin & Barneby.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 13011973) with original publication details: N. Amer. Fl. 23(4): 263 1930.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:186622-2.
This name was in version 1 of The Plant List, record tro-13011973.