Hear the Difference: Audio Breakdown and Phonetic Guide to Saying 'Peony'
Horticulturists and professional nursery growers operate with a second vocabulary: botanical Latin names. This creates another layer of cross-contamination between vernacular speech and trade jargon.
The scientific genus is Paeonia, named after Paeon, the physician of the gods in Greek myth who used the plant's roots to heal Hades. Under the rules of botanical Latin pronunciation, diphthongs like ae convert into an /iː/ sound, and the penultimate syllable takes the weight: pee-OH-nee-uh (/piːˈoʊniə/).
Because growers spend their days reading seed tags marked Paeonia lactiflora or Paeonia suffruticosa, their brains default to second-syllable emphasis. When they switch back to everyday English, they often drop only the final "-a," leaving behind "pee-OH-nee."
Neither side of the counter is deliberately mangling the word. The customer is speaking standard broadcast English, while the grower is simply translating scientific Latin into casual speech.