The patent is on "novel" sequences, like "Roundup-Ready", but plants have a tendency to broadcast (old meaning) their genome (e.g., pollen).
Interesting you should mention that tendency to "broadcast", because Monsanto engineered their seeds to not do that (see: the "terminator gene") but did not put it into production because of the huge backlash it caused.
The terminator gene made them still broadcast, but the end result was sterile seeds. Which is definitely a risky option to take, and deserves backlash.
New species are created all the time, such as though cross-breeding.