When Calico Dutchman's Pipevine (Aristolochia littoralis) flowers, you really can't miss it. The blooms are the size of dinner plates, and up close the smell is fairly unpleasant. Still, the blooms are fascinating in color and shape.
Honestly, we probably shouldn't have this vine in our yard. A. littoralis is invasive in Florida (it's currently on the FLEPPC Category II list). We keep it around for the Polydamas Swallowtail caterpillars to feed on. However, because it's from South America, it's actually toxic to the Pipevine Swallowtail caterpillars who also can accidentally lay on it.
Fortunately, it's easy to tell the eggs of the two species apart, so by watching the vines carefully for eggs, we can remove the red ones of the Pipevine ST to the native A. tomentosa that we also grow. (Polydamas eggs are yellow.) If you're not willing to take the time to do this, it's probably best for butterfly gardeners to eliminate A. littoralis from the yard to avoid harming our native butterflies.