It surprised me that my attention got drawn on that big shrub by the river as the flowers were as green as the foliage, but they were big and bell-shaped, I think around 10cm.
I thought maybe in the Solanaceae family but couldn't find a match so far..
Funny is that while I was focusing on one of the flowers and at the exact moment I pressed the shutter, a hummingbird came feeding on it, that was luck!

Ants seemed to be fond of it too..

Everything about the plant reminds me of Iochroma australe which I once had Myriam, so Solanaceae seems most likely. The flowers look like a cross between Brugmansia and Cobaea!

I'm looking .. seem to have lost the tropical plants site I once used.

Solandra looks similar ..

http://ceb.wikipedia.org/wiki/...

http://plantillustrations.org/...

Look at fig. 43 on this pdf .. although I can't work out if there's an example given!

http://www.anatomiavegetal.ib....

The google link to the pdf offered a translation, there's no diagrams although the pages and figure no.'s are given.

http://translate.google.co.uk/...

I picked out an example of Bignoniaceae after #45 but that looks less likely.

I went backwards on the plantillustrations site, found Markea viridiflora or Solandra viridiflora ..

http://plantillustrations.org/...

I couldn't get the Brazil site to check, so googled and found a name in a link, Dyssochroma viridiflora ..

https://www.google.co.uk/searc...

https://www.google.co.uk/searc...

https://www.flickr.com/search/...

http://www.academia.edu/162244...

Dyssochroma viridiflora appears to be the same plant as Markea viridiflora, although the plantlist says they are both accepted names, the reference to 'Ducke' is given.

http://www.solanaceasnobrasil....

http://www.theplantlist.org/tp...

http://www.theplantlist.org/tp...

I feel that Dyssochroma viridiflora is THE one Janet! You are unbeatable!

Thanks for the acorns.