One of Our Weirdest Native Plants – The Wild Cucumber

Those venturing out onto our local trails this time of year are bound to notice light green vines growing out across the trails and climbing up into the surrounding chaparral. Walk the same trail the next day and the vines will be twice as long – they grow that fast. In just a few weeks these vines will produce fruit that are absolutely one of the weirder sights you will see in our mountains – nasty little green orbs covered in scary-looking spikes. I’m sure you’ve seen them. They have a distinctly alien look, and they look startlingly out-of-place. But they aren’t. They’re a California native – the wild cucumber.

Like many native plants the wild cucumber is known by several names, some with interesting origins. “Cucumber” because in some of its variations throughout the western states the fruit is less spikey, and does look a little cucumber-like. It’s also called “manroot” or “old man in the ground.” The vines grow from a perennial tuber, or root, that gets huge with age, sometimes over a hundred pounds. This large root divides into “legs” and looks vaguely human when dug up. The plant’s real name is “Marah,” after a Biblical place-name mentioned in Exodus, where the Moses-led Israelites came to a well where the water was too bitter to drink. The plant is indeed extremely bitter to the taste, and thus the name.

The huge tuber slumbers underground through the summer and fall, dormant, but after the first rain of winter, the vines explode up out of the ground and take off in every direction. Its strategy is to take advantage of the short-term abundance of water and grow as fast as it can. It quickly pushes out a few leaves for photosynthesis and some small white flowers for reproduction. As some flowers are male and others female, it self-germinates. The fruit – the “cucumbers” – develop quickly and, after the last rain of our short rainy season, the plant goes dormant again. The vines dry up, and the spikey fruit turns yellow, then tan in color. The seeds drop out of the dried up cucumbers, which are generally eaten by various birds and animals. But the strength of the plant is stored in the huge underground tuber. The vines can be cut off, year after year, as they often are near trails, and they just keep coming back from the stored energy in the root. It survives fires as well, and is often the first plant to re-appear.

Although the plants, fruit and seeds are inedible, even poisonous to humans, the local Indians, who used everything in their natural world, found uses for wild cucumber. The vines and fruit were mashed into poultices and soaking solutions for various ailments. The tuber was, like yucca root, used as soap. Some tribes mashed the fruit and root, and placed it in streams. The wild cucumber contains a chemical that apparently denies oxygen to fish in the stream, stunning them, and causing them to float to the surface. The roots and seeds were also used by the Indians as a purgative. This seems to be the only use the white man picked up. California wild cucumber was the active ingredient in Stoughton’s Bitters, a popular laxative of the 19th century. And of course there’s the notorious rumor that is applied to so many native plants – that the plant has hallucinogenic properties. As the plant is somewhat poisonous, it seems a pretty risky high.

In most of the U.S., winter is a time of bare plants and brown ground cover. The plants come alive in spring and stay brilliant green all summer from the frequent summer rains. Here in Southern California, it’s just the opposite. Many native plants take advantage of our short winter rains with a growth spurt, then hunker down and try to survive the coming several months of no rain.

So as you venture out onto our local trails, say hello to the prickly wild cucumber, a true California native plant, and one that reflects so well our seemingly backward natural growing season.

  mike lawler