The [eastern] black swallowtail [Papilio polyxenes], also called the American swallowtail or parsnip swallowtail, is a butterfly found throughout much of North America. It is the state butterfly of Oklahoma.
The black swallowtail has a wingspan of 8 to 11 cm [3.1 to 4.3 in]. The upper surface of the wings is mostly black. On the inner edge of the hindwing is a black spot centered in larger orange spot. A male of this species has a yellow band near edge of wings; a female has row of yellow spots. The hindwing of the female has an iridescent blue band.
Photos: Atlanta Botanical Garden, Atlanta, Georgia, USA 
^ Female: Black black with shadows of dark stripes.
The Eastern Tiger Swallowtail [Papilio glaucus] is a species of swallowtail butterfly native to North America. It is one of the most familiar butterflies in the eastern United States, where it is common in many different habitats. It flies from spring to fall, during which it produces two to three broods. Adults feed on the nectar of many species of flowers, mostly from those of the Apocynaceae, Asteraceae, and Fabaceae families.
Papilio glaucus has a wingspan measuring 7.9 to 14 cm [3.1 to 5.5 in]. The male is yellow with four black “tiger stripes” on each fore wing.
Females may be either yellow or black, making them dimorphic. The yellow morph is similar to the male, but with a conspicuous band of blue spots along the hindwind, while the dark morph is almost completely black.
Photo: Dawsonville, GA. , Cecil B. Day Butterfly Center, Callaway Gardens, GA , Brevard, NC, USA 
The Anise Swallowtail, Papilio zelicaon, is a common swallowtail butterfly of western North America. Both the upper and lower sides of its wings are black, but the upper wing has a broad yellow stripe across it, which gives the butterfly an overall yellow appearance. There are striking blue spots on the rear edge of the rear wing, and the characteristic tails of the swallowtails. Its wingspan is 7–9 cm. Its body is somewhat shorter than the rather similar Western Tiger Swallowtail, with which its range overlaps; it also lacks the black stripes, converging toward the tail, of the latter. There is a somewhat darker subspecies, Papilio zelicaon nitra, which is rare throughout the range, though somewhat more often found at lower elevations.
^ The above caterpillars and chrysalis was found on Foeniculum vulgare [Fennel], its host plant.
The Anise Swallowtail is a butterfly of fairly open country, and is most likely to be seen on bare hills or mountains, in fields or at the roadside. It is often seen in towns, in gardens or vacant lots.
Photo: Atlanta, GA. 
Papilio lorquinianus, the Sea Green Swallowtail, is a butterfly of the Papilionidae family. It is found in Indonesia, Sulawesi, Borneo, Java, Sumatra and in the Philippines.
Photos: Sentosa Butterfly Park & Insect Kingdom, Singapore 
^ Plant: Sweet basil [Ocimum basilicum].
Papilio demoleus malayanus has many common names including Common Lime Butterfly, Lemon Butterfly, Lime Swallowtail, Small Citrus Butterfly, Chequered Swallowtail, Dingy Swallowtail, Citrus Swallowtail.
Papilio demoleus malayanus is a common and widespread butterfly in Singapore. It gets its common names from its host plants, which are citrus species: Citrus aurantifolia [Key Lime], Citrus grandis [Pomelo]. Unlike most swallowtail butterflies, it does not have a prominent tail.
Photos: Oh Farms & Butterfly Garden, HortPark, Singapore, 20130126
When you have spare time at Changi Airport Singapore, look for Nature Trail Airport Gardens. I visited the Butterfly Garden, located at Changi Airport Terminal 3’s Departure and Transit Mall. Its free and it is open 24 hrs. It is home to more than 1,000 free flying singapore butterflies, and close to 50 butterfly species native to Singapore and Malaysia were specifically selected to be bred in the butterfly garden.
I was there close to midnight and it was dark but I was able to photographed some. Enjoy!
Here are upside down Clipper butterflies [Parthenos sylvia philippensis].
Below are Mangrove Tree Nymph [Idea leuconoe chersonesia]
^ They’re not mating pair. A single butterfly and its reflection 🙂
Next, Common Mormon [Papilio polytes].
Below is Great Eggfly [Hypolimnas bolina bolina]
and Leopard Lacewing [Cethosia cyane].