Sorry for my inexperience -  what wood is pictured below?

It's the underside of the top of an old plain desk I plan to harvest wood from for the group chair project. (It pains me to chop up perfectly functional furniture. But it's gone  unwanted. ReStore even coated it in milk pant trying to sell it.)

Dragging my thumbnail doesn't feel the grain on an unfinished section and I can't dent it with a thumbnail.

I'm no expert but my guess is red oak.

Guessing wood from a photo is hard. Not like guessing how a shoe fits from a photo, but still hard.

Having now cut some of it, it doesn't smell like oak, at least not like any I've ever cut. A bit swampy & a little spicey? My nose doesn't have an extensive vocabulary, so I can't say exactly what it did smell like. 

I second Tim. Looks like Mahogany.