Hi Unc. There are a few different kinds of Poplar. The kind they sell at lumber yards is Liriodendron, as Unc noted. It's never as pale as the wood in the OP photos, it has an olive green hue when fresh cut; eventually it turns brown. IME it's quite hard, similar to soft maple. I'm guessing that body is basswood. It could be some asian species that we, here in the states, aren't familiar with, .
All the poplar I've ever seen for sale is Liriodendron- it is usually greenish, but sapwood is sort of a dirty cream and some pieces (which I always sought out) are purplish to nearly black. Perhaps in some parts of the country true poplar is available, though I've never seen it. Poplar (tulipwood) is 540 on the Janka hardness scale; for comparison, hard maple is 1450 and cocobolo is 2960.