The Ark in Space has a wonderful article about the Swallowtail butterfly. A familiar site around the world, yet many people have only seen the Common Yellow variety. However, there is much more to this family of exquisite insects, from the Emerald to the Zebra variety (and no prizes for guessing why they received those names). Take a look at the unusual side of the Swallowtail along with one or two varieties of which you may already be aware.
From the aricle:
Name a green butterfly, apart from the one above. Yes, you're right, there are not many of them around and the Emerald, Papilio palinurus, is one of the very few extant green species of butterflies in the world. The Emerald is found in South East Asia, particularly the rainforest of Malaysia.
Image Credit Flickr User guiss95