It might have come from a garden, or the Botanical Gardens.
It's interesting that this looks much like Marcgravia rectiflora which on your other Macragravia you found that Marcgravia umbellata is now synonym for Marcgravia rectiflora on the Catalogue of Life.
http://garden.org/thread/view_...
The IPNI links for both on the Plant List doesn't mention a change in name, and Marcgravia rectiflora was updated in 2016 but by a different person than on the Catalogue of Life. Marcgravia umbellata wasn't updated since 2008, if the name had changed you would have thought a note would have been put on that entry and the Plant List entry altered to being a synonym. Both have different orgin dates with Marcgravia umbellata being the earlier of the two.
http://garden.org/thread/view_...
I found on the Catalogue of Life that Marcgravia umbellata is also accepted, the fact that it has been given as synonym for another species doesn't mean it hasn't species status in it's own right. It often means that one species has, at some time in history, been mistaken for another species and found at a later date to be a different species, so the name is given as a synonym only to reflect that it had been confused with another species at some time in history.
http://www.catalogueoflife.org...
http://www.catalogueoflife.org...
