How many species of peonies are there in the wild? How many cultivars in gardens?

Answer

The current scientific review by Dr. Hong recognizes 54 species in the wild. His most recent review in English is Peonies of the world: taxonomy and phytogeography, published by the Royal Botanic Gardens, Kew, in 2010. The number of species found in the wild is quite different from the number of cultivars (human selections) found in gardens. Over 20,000 cultivars have been described since the 1800s but most have already disappeared and are assumed extinct.