How to read the band →
Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Iris
Iris has been climbing in recent years. All-time it's been given to 102,320 U.S. babies, the 229th most common name by sound today, peaking at 3,741 in 2025, with 3,741 in 2025.
Iris has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).