I've turned tulip poplar quite a bit since last year. The county was widening our road, and cut down, hackberry, poplar, oak, pecan, and elm. So, being right outside my house and all, me and another fellow just followed along behind them and collected about 4 truck loads, haha.
This is tulip poplar, with some spalt. If not spalted, it is pretty white/silver, with a greenish heart.
The only solution i had for the tearout, (which happened no matter what tool i used, or how sharp), was with sanding. It goes away, and leaves you with a great finishing surface. The wood is really soft, and light. Probably the softest wood I've ever turned. I guess that is the contributing factor to the tearout, cause it's not very dense. Or, this particular tree wasn't, anyway.