begonia

The English word comes from the translingual genus name Begonia, which was coined to honor Michel Bégon (1638–1710), the French governor of Saint-Domingue. His surname, Bégon, traces back through French to a Latin name, Bego.

The word began as a personal name and was borrowed into scientific Latin as a genus label for a group of plants; English then took the genus name directly as the common name for the flower.

The facts don't establish any cognate English words tied to this name — it stands as a direct borrowing from the botanical genus name.