Polygonia harroldi (male)
 
Polygoniais a genus of butterflies with a conspicuous white mark on the underside of each hindwing, hence the common name comma.You  can observe this butterfly in North America, Canada and USA. 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 in the genus Polygonia are referred to collectively as the anglewings. The eastern comma, Polygonia comma (Harris), is also known as the hop merchant and the comma anglewing (Miller 1992). It is a relative small inconspicuous butterfly that is rather closely associated with moist woods where its preferred nettle hosts grow, but it sometimes strays into other areas. With its wings folded, it resembles a dead leaf and is highly cryptic.