That would be a Kemet brand capacitor. It is marked with a "+" but isn't real clear about it. Rotate the part to find the voltage rating, the "+" sign is oriented towards the positive end.
Marking is even worse with the dipped type capacitors -- you have to look for the teeny-tiny "+" symbol near one leg. Often there is a stripe near the "+" symbol making it look like one big negative symbol.
Don't get these in backwards! Tantalums don't take nicely to that!