D Dog,
using your example of your Bloodhound and my Field Spaniel, these would not be classed a separate species in the evolutionary scope, as these breeds of dog can procreate together. Producing another dog. (of coarse the copulation process would be quite amusing to watch).
With the plants I mentioned, it was observed that naturally occurring hybridization created a plant that WILL ONLY pollinate with the same new type of plant. That new plant, is a new species.
The definition of species used is the broad definition used by most.
In the reviewed link you posted you will see that the definition of 'new species' given to these plants holds.
In the classical creationist definition, a species is known as 'type' or 'kind'. That being that each animal and plant alive now and through-out history, have always been the same, unchanged, plant or animal, as created by God (and Jesus). What these new plants observably demonstrate is that they were not created by God, but naturally evolved.
I hope my definition and explaination helps.
steve
steve