One of my favorite trees here in Buenos Aires is the Palo Borracho. I first encountered them along 9 de julio, specifically at the Independencia subte stop along the C-line. There is a gorgeous row of about half a dozen rotund prickly trees. Their oval trunks remind me of chianti bottles that you see as candleholders in Italian restaurants. I have been told they are only full like this when there is water below for them to store. Palo Borracho means "drunken pole" and I'm not sure if it refers to fact that they store water or if they look like a wine bottle, either way it fits. Their trunks have a green tinge to them and when young are covered in thick sharp thorns. As they age, the thorns fade from their aged bodies and relocate to their younger extremities. I'm not sure what they are protecting against, but damn they are sharp and not to be messed with.
In the spring, avocado-like seedpods dangle from their branches in hard green shells. As time goes by, or as parrots attack, they burst open and the fluffy cotton insides fly all over the place making a mess. As spring turns into summer, buds form and the large lily-like flowers open up. Most of the palo borracho trees in Buenos Aires have pink flowers, but some are somewhere in between white and yellow. I prefer the luscious pink flowers. They are a sight to behold. I've mostly seen young palo borracho trees here specifically planted in the parks. Once, I did see one growing in the crack of a roof terrace in a one story building in San Telmo. Not sure which will go first, the tree or the building.
You can see more photos of these beautiful trees on my flickr stream.