In this case, weedy rice (Oryza sativa f. spontanea) is actually just the same species as cultivated rice (O. sativa), and the two do interbreed freely (as per

In this case, weedy rice (Oryza sativa f. spontanea) is actually just the same species as cultivated rice (O. sativa), and the two do interbreed freely (as per definition of species in plants).