The Jaca (Artocarpus heterophyllus) is one of several fruits well known in Brazil, but unlikely to find itself in a supermarket in England. Actually it's originally from Asia, and is for example, the national fruit of Bangladesh.
The Jaca, or Jack fruit to give it it's English name, holds the distinction of being the largest fruit in the world, reaching an incredible 36 kg in weight! Because of this the fruit are not out on the branches, which would break under the stress, but hang directly from the trunk. The trees themselves are large and stately reaching up to 25m high.
As I said, the Jaca originates in Asia, and was probalby transported to Brazil from Kerala by the Portuguese. But it flourishes in the Mata atlantica, and indeed is sometimes considered a pest! It's fruit are eagerly devoured by coati, which then deposit the seeds around the forest, where the fast growing Jaca (1.5m/yr!) often out strips native species. This also artificially boosts numbers of coati who then go on to raid nests for eggs and nestlings. Because of this national parks often clear wild Jaca saplings, with, for example, over 50,000 being culled from the Tijuca Forest park near Rio between 2002 and 2007.
Eating a jackfruit is, problematic. Firstly, mature fruit emit a strong, distinctive smell, said to resemble rotting onions. Secondly, the fruit is covered in spines, thirdly cutting the fruit relesaes a sticky latex which will accumilate on knives and skin unless pre-coated with cooking oil. And fourth, the flesh tastes of banana, which is itself enough to dissuade this author!
Although there seem to be many delicious recipes for Jaca from Asia, I could not find any from Brazil. The fruit is ususually eaten fresh, or as a juice. Take care though, the flesh is hard to digest, and, anecdotally, several people have died from getting carried away and eating a whole one!