It can refer to a) a Mango Tree (mangueira in Portuguese, or pé de manga too), b) to the famous carioca Samba School, Estação Primeira de Mangueira (aka Mangueira), or yet to c) a hose. It really depends on the context.
- Você vai na mangueira hoje a noite? (probably the samba school, since not a lot of people go to mango trees at night... I believe; and since a hose here wouldn't make any sense)