I've read in several places (can get references if necessary) that oaks
( Quercus spp.) hybridize very easily. If so, wouldn't - over
millennia - speciation be lost and all oaks blend to a single
homogeneous oak? If hybridization is so easy - what keeps the species
apart? How does tell if a particular "wierd" specimen is a hybrid or a
new species? Am I expecting botany to be too exact?

If DNA analysis was extremely inexpensive (say, $ .10) would botanical
taxonomy be void of ambiguity?