Have you got a wood specialty store like the Windsor plywood chain?
I'd ask for drawer-side= carefully milled 1/2" x 6" poplar.
Seems to have the needed dimensional stability for furnishings like, you guessed it, drawer sides.
I carve the stuff for wood-cut printing, holds reasonably good detail, nice to carve.
Construction lumber here, from 1x2 up to 2x12 is graded according to COFI
Council of Forest Industries. Stamped COFI/SPF
Could be spruce (Picea sp.),
might be pine (Pinus sp.),
might be fir (Abies, not D-fir).
The pine these days is bug-wood, you can see the bluestain fungus carried by Mountain Pine Beetle.
Come on up! We have 18,000,000 ha of standing dead pine in BC that's so dry and cracked, it's good only
for stove pellet sawdust. I do my duty and burn 10,000lb/winter.