The underside is chalky white to pale grey with tiny dark grey spots and a zigzagged submarginal line on the hindwing. |
Marginal and submarginal meristems on opposite flanks of the primordium initiate leaf-blade formation. |
The placenta is usually located in a region corresponding somewhat to the margins of a leaf but is actually submarginal in position. |
It is best distinguished from the Canadian Tiger Swallowtail by the entirely yellow lunular submarginal spots on the underside of the hindwing. |
The female has orange forewings with prominent black spots and an orange submarginal zigzag band on the hindwing upperside. |
The wings with one marginal and three submarginal cells, and one recurrent nervure. |