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"
"water"
"son of Benedict/Ben"
"Wild cat with short tail and tufted ears"
"from Fairday, English place name"
"possibly derived from Karl, meaning free man"
"vintage, growth (as in wine)"
"life, living"
"noble, excellent"
"life, living"
"wisdom, chief, intelligence"
"light, torch"
"king's woodland clearing, king's meadow"
"of the stars; radiant star"
"noble, nobility"
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.