Daan,
North america has a much greater diversity of trees than Europe. And, unfortunately, many trees get names that are not related to their genus.
We have two families of poplars. One is "populus" which are upland trees some of which grow in the mountains but the family, in general, does not produce much desireable lumber.
The other poplar is "lirodendrum tulipflora". Called "tulip tree", because it has a tulip-like flower,and "tulip poplar",or "yellow poplar". It is also called "the lumber tree" because it grows fast, achieves heights of 100 feet or more and can produce large amounts of straight-grained lumber. That is probably what you have. It is used for painted funiture because it is very bland. And it is not very rot resistant so make certain yours stays well sealed.

: I am building a Night Heron out of poplar strips. The density is
: round 0.4. WRC is 0.3 and Fir 0.6 so light enough. It is much
: stronger than WRC and here in Holland much cheaper.
: It bends very well and is carved easy with knife and plane.

: Here in Holland they made wooden shoes of this material for ages.
: The more expensive wooden shoes are from willow.
: This poplar is very light.
: Between december and now I did not have any progress but you can
: see some pictures on http://www.ddaniels.com/dhwblog

: Greetings from Daan Daniels in The Netherlands