The DU Lounge

I read about that mango tree, and others there, a half century ago in Popenoe's "Manual of Tropical and Subtropical Fruits" (1920).

"In the Botanic Garden at Rio de Janeiro, Brazil, there is a
magnificent avenue of mango trees planted by the emperor Dom
João VI more than a century ago. So far as known these trees
have never matured any fruits . They blossom, and occasionally
set fruits, but the latter invariably drop off before reaching
maturity. J. C. Willis, former director of the garden, attributes
this to the fact that they are planted on low wet ground."

And the "not quite sunflowers" look to be a double form of Tithonia diversifolia, the Mexican sunflower. I have the single form in my garden, they produce a good amount of biomass in marginal soils.

It looks like you had an amazing trip.