This name is a synonym of Handroanthus umbellatus (Sond.) Mattos.
The record derives from iPlants
(data supplied on 2012-03-23)
which reports it as a synonym (record 317158) with original publication details: Loefgrenia 50: 2 1970.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:117336-2.
This name was in version 1 of The Plant List, record kew-317158, and has not been changed.