im not trying to come off as an ass but.....
poplar and basswood are of the same family. i want to say that they stem from the linden tree.
but i may be wrong.
as far as bolt on guitars go, the wood has nothing, literally nothing to do with the sound of the instrument.
if you want some sort of proof, i recently made a mahog tele body for a guy in town(57 tele with later pickups)
the originaly body was a 3 peice ash body, and the body i made him was a single peice, he hesitated thinking that it would change his "tone"
but after it was completed he was suprised that his "tone" was exactly the same.
the wood made no difference, except for wieght.
i got a video on youtube of the guitar after i first made the body and did a dry run, i should have done a video of the beast before i made the new body.
the only time that wood really makes a difference is in an archtop or acoustic setting, and even then the bracing will determine the overall sound.