Complex sentence: Between 65 and 300 species are recognised, depending on the circumscription of the genus; some botanists divide the genus into several smaller genera, including "Fagopyrum", "Fallopia" and "Persicaria".
Split into simpler sentences: Between 65 and 300 species have been recognised at various times, depending on the circumscription of the genus. A number of species that had been included in "Polygonum" have been moved into several other genera, including "Fagopyrum", "Fallopia" and "Persicaria".