Polygonia (from Greek πολύς - polys, "many" and γωνία - gōnia, "angle") is a genus of butterflies with a conspicuous white mark on the underside of each hindwing, hence the common name comma.
They also have conspicuous angular notches on the outer edges of their forewings, hence the other common name anglewing butterflies.
The related genus Nymphalis also includes some anglewing species; Polygonia is sometimes classified as a subgenus of Nymphalis.

Many members of Polygonia hibernate as adults.

Species include:
Polygonia c-album (Linnaeus, 1758) – comma
Polygonia c-aureum (Linnaeus, 1758) – Asian comma
Polygonia comma (Harris, 1842) – eastern comma
Polygonia egea (Cramer, 1775) – southern comma
Polygonia faunus (Edwards, 1862) – Faunus anglewing, Faunus comma, green comma
Polygonia g-argenteum Doubleday & Hewitson, 1846 – Mexican anglewing
Polygonia gigantea (Leech, 1883) – giant comma
Polygonia gracilis (Grote & Robinson, 1867) – hoary comma
Polygonia haroldii Dewitz, 1877 – spotless anglewing
Polygonia interposita (Staudinger, 1881)
Polygonia interrogationis (Fabricius, 1798) – question mark
Polygonia oreas (Edwards, 1869) – oreas anglewing, oreas comma, sylvan anglewing
Polygonia progne (Cramer, 1775) – grey comma, gray comma
Polygonia satyrus (Edwards, 1869) – satyr anglewing, satyr comma
Polygonia undina (Grum-Grshimailo, 1890)
Polygonia zephyrus (Edwards, 1870) – zephyr comma
Polygonia (from Greek πολύς - polys, "many" and γωνία - gōnia, "angle") is a genus of butterflies with a conspicuous white mark on the underside of each hindwing, hence the common name comma. They also have conspicuous angular notches on the outer edges of their forewings, hence the other common name anglewing butterflies. The related genus Nymphalis also includes some anglewing species; Polygonia is sometimes classified as a subgenus of Nymphalis.
Many members of Polygonia hibernate as adults. 
Species include:
Polygonia c-album (Linnaeus, 1758) – comma
Polygonia c-aureum (Linnaeus, 1758) – Asian comma
Polygonia comma (Harris, 1842) – eastern comma
Polygonia egea (Cramer, 1775) – southern comma
Polygonia faunus (Edwards, 1862) – Faunus anglewing, Faunus comma, green comma
Polygonia g-argenteum Doubleday & Hewitson, 1846 – Mexican anglewing
Polygonia gigantea (Leech, 1883) – giant comma
Polygonia gracilis (Grote & Robinson, 1867) – hoary comma
Polygonia haroldii Dewitz, 1877 – spotless anglewing
Polygonia interposita (Staudinger, 1881)
Polygonia interrogationis (Fabricius, 1798) – question mark
Polygonia oreas (Edwards, 1869) – oreas anglewing, oreas comma, sylvan anglewing
Polygonia progne (Cramer, 1775) – grey comma, gray comma
Polygonia satyrus (Edwards, 1869) – satyr anglewing, satyr comma
Polygonia undina (Grum-Grshimailo, 1890)
Polygonia zephyrus (Edwards, 1870) – zephyr comma
Polygonia