Picanha is a cut of beef popular in Brazil. In the U.S. it is little known, but referred to as the rump cover or rump cap. North American butchers generally divide it into other cuts like the rump, the round and the loin. In some places in the US it is called top sirloin cap. 
In Brazil, the most prized cut of meat tends to be the picanha. In Brazil, the fat is not removed from the cut until the steak has been cooked. In the U.S., however, the fat tends to be cut down at the butcher shop unless otherwise directed by the customer.