One of the many treats that Hawaiians look forward to is when the Liliko’i “go off,” heralding the time when the Liliko’i fruits ripen and fall off the vine. This makes for some lovely snacks while on a stroll or later, in preserved jams or syrups.
When they arrived in South America, Christian missionaries named the Liliko’i “Passion Fruit,” not passion as in *ahem* physical passion, but as in (cue the heavenly chorus) the Passion of the Christ, so named because of its physical attributes of color, number of stamen parts, and other symbolic features representing various associations with Christ. In 1923, a Mr. E. N. Reasoner brought the seeds to Hawai'i and they have done very well here since.
Liliko'i vines, (genus Passiflora) have a fascinating evolutionary story! Unlike many flowers, Liliko’i cannot self-pollinate. They use their scent, combined with their wildly adorned flowers to attract pollinators. In Hawaii, the most common are Carpenter Bees (genus Bombex), or purposeful humans. Over time, the fruit ripens into a tasty pod filled with sweet juicy pulp and edible seeds! My, my! But Consumer Beware! Wait to eat the fruit until it falls to the ground! If you pick a Liliko’i off the vine, there are toxins in the seeds that can incapacitate you if eaten early, which is never a good thing.
There is a fascinating story of the ancient, chemical warfare between the Passiflora vines and its ancient nemesis, the caterpillar (larva form) of the Heliconid butterflies, also called the Long-winged Butterflies. (Of the approximately 80 species of Long-winged Butterflies, here in Hawai’i, we have only the Gulf Fritillary, usually native to the southern mainland US and Mexico but now, well established on all the Hawaiian islands.) There is a constant battle between plant and animal, both competing in an ancient strategy of one-upmanship.
The Passiflora has tried to rid itself of the caterpillars by increasing the toxicity levels of the host plant. The caterpillars of Long-wings have adapted. The toxicity increases. (The vine contains chemicals that are so toxic that a mouse can have a heart attack if it eats a vine.) But the Long-winged larva has not only learned how to adapt to these toxins, they are able to sequester them into its body and retain the poisons even after their metamorphosis into butterflies, who then advertise their toxicity by displaying bright colors on their wings! Wow!
The Liliko’i has diversified its attempts to trick its enemies. Since many butterflies depend on shape recognition to spot their host plant, passion plants have evolved many different shapes to their leaves to confuse the butterflies! Some even have developed butterfly egg shaped nodules on their stems to mimic the presence of another butterfly’s eggs, thereby discouraging other butterflies from laying their eggs in close proximity to competitors. Amazing!
And, as always in the natural world, the struggle for survival continues…