The mostly white and blue common passion flower likely remains the most popular. After all, it is the weirdest. Elaborate and disproportionate floral parts imply that it is of another planet. Red passion flower, Passiflora racemosa, although less peculiar, is perhaps a bit more colorful. Its brick red flowers bloom randomly for as long as weather remains warm. 

Flowers are about three or four inches wide. They develop in open racemes that seem to spread out somewhat evenly over the exterior of their foliage. Bloom is not profuse, but is somewhat continuous until autumn. Newer flowers replace older flowers within the same racemes. Leaves are as wide as their flowers, with three blunt lobes and axillary tendrils. 

The lushly evergreen foliage can get shabby through winter, or completely ruined by just mild frost. It regenerates vigorously though. Aggressive pruning as winter finishes delays bloom, but promotes vigorous growth. Vines can potentially reach more than twenty feet. Fruit is rare without manual pollination. Fruit flavor can be bland without tropical warmth.