The monarch butterfly (Danaus plexippus) is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. It may be the most familiar North American butterfly. Its wings feature an easily recognizable orange and black pattern, with a wingspan of 8.9–10.2 cm (3½–4 in) (the viceroy butterfly is similar in color and pattern, but is markedly smaller, and has an extra black stripe across the hind wing).

Source:Wikipedia