Projectile Cucumbers

By Laura Yayac

wild-cucumberThe orbs dangle, pale green with darker stripes, like adorable baby watermelons on a vine of curls. Each one rests under its own leaf awning. Get closer, though, and you’ll see that this is no ordinary miniature fruit. Covered in spikes and ready to impale, it is at once magical and ominous. And that’s not the last of its tricks.

My encounter with the wild cucumber (Echinocystis lobata), a cousin of the ordinary garden variety, released my inner nature nerd. Are the wild cucumber fruits edible? If many plants rely on animals to eat their fruit and disperse the seeds, why the thorns on this fruit? How else would the seeds spread? I watched the crazy fruit over several weeks as it opened and split at the bottom – what triggered that process?

The answers were fittingly stellar for such a spectacular fruit.

Wild cucumber is not edible for humans, though the root is sometimes used for medicinal purposes, either ground into powder or brewed as a tea. I’m still not sure why spikes cover the fruit; perhaps it’s because wild cucumber doesn’t need animals to disperse. To spread its seed, this plant does not mess around.

While birds and small mammals sometimes feed on this plant, it primarily spreads its seeds by expelling them with “hydrostatic pressure.” The plant builds up water pressure against a membrane within, and when the pressure is great enough it shoots the seeds out. In other words, these little spike balls launch their seeds like missiles. The plant can disperse its seeds as fast as 11.5m/sec.

Wild cucumber bears fruit in the late summer and early fall, and is usually found in wet edge areas; it doesn’t grow well in shade. Hunt for these mysterious plants, climbing their way up trees and shrubs, along floodplains, meadow borders and road edges. Later in the season, the fruits dry out and turn to skeletal husks. They remain suspended from the vine and look, as a fellow naturalist described them, like fairy lanterns. These plants are weird. Now is the time to go find one and indulge your inner nature nerd.

As a member of a bountiful CSA this fall, Laura Yayac has recently described her life as a race against vegetables. Each week she roasts, sautés, and steams her way to an empty produce drawer and a full stomach. She has discovered just how far one gigantic cabbage goes – approximately 23 meals. Laura is also an Ecological Planner.