Mysterious Green Things

In Brazil last summer, I wandered around Parque Ibirapuera, with my SO's little sister, who I'd met only days before.  We were bonding, I suppose, in that awkward way to people do when they love a common person.
 

Ibirapuera is huge, compared to Central Park in importance to São Paulo.  It is a wild version of a city park, covered in foliage that, here in the States, you buy for your home.  There were kids longboarding, families strolling, and us, walking more or less in silence.  Until I saw baskets of green things.  Not baskets, shopping carts.  Shopping carts full of something natural, next to stands, occasionally staffed. 

The Mysterious Baskets, Green Things, etc.

 

 

What were these wonders?  Why were there piles of them? 

Me: Laura, what are those?
Laura: (confused at my ignorance) Coconuts.
Me: Whaaaa?  But coconuts are brown and hairy.
Laura: Not so much.
Me: But why are they there, what does it mean?
Laura: Haven't you ever had coconut water before?
(I think here is a good place to note: Laura speaks with a slight Australian accent that I give her no little grief about.  Also, she's Brazilian.)

Yes, coconut water.  Fresh from a coconut.  The attendant rammed the top with a chisel, and dumped the contents in a cooler, keeping up a stream of conversation.  Apparently, there was a problem in the park with people throwing empty coconuts at each other, that's why they could no longer serve the water straight from the coconut.  She handed me a cheap plastic bottle full of the stuff.