Petunia sits next to 4 phonetic neighbors — Begonia, Gardenia, and Lavinia are the closest matches by sound. Most share Petunia's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"petunia flower"
"beloved, dear"
"king's woodland clearing, king's meadow"
"breath of life"
"my people"
"son of the blessed one"
"vintage, growth (as in wine)"
"bird"
"from Fairday, English place name"
"Wild cat with short tail and tufted ears"
"possibly derived from Karl, meaning free man"
"noble, nobility"
"beautiful, all"
"of the stars; radiant star"
Similar sound: These names share phonetic patterns with Petunia — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin botanical origins, giving them the same cultural heritage as Petunia.
Rhythm: Petunia is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.