Wild Cucumber (Repeat)

 A version of this was first published in 2013 and very popular (tens of thousands of views)

Wild cucumber showing leaves, tendrils and flower spikes

Wild cucumber, also known as prickly cucumber or balsam apple, is a plant species native to North America but with the annoying habits of some invasive plants. It is a fast-growing annual vine propagated by seeds. This slender-stemmed vine can quickly blanket low plants or tendril its way 15-20 feet up trees.

During July and August the vines display white flowers, followed by the development of seed pods that superficially resemble a spiky cucumber approximately two inches in length. Once the seed pods mature they dry out and disperse from the bottom several large black seeds the size of pumpkin seeds. Wild cucumber dies with the first frosts of fall.

Wild cucumber pods open from the bottom and seeds fall

The Linnaean name, Echinocystis lobata, comes from Echino for spiny and cystis for bladder-like in appearance. Lobata refers to the shape of the leaves. Echinocystis is native to the central, eastern and northern states, up into Canada. It is not found in the southwest, but confusingly, there are distantly related plants in southern California that also go by the name wild cucumber.

The latter are in the family Marah, with several related species. These are all fast-growing vines with tendrils and seed pods that superficially resemble a spiky cucumber, but Marah are perennials not annuals, with each year's new growth sprouting from a huge tuberous root that can weigh more than 100 pounds.

In Maynard, there is currently a patch of wild cucumber near where the Rail Trail is parallel to High Street (a dead end street behind Jimmie's gas station). 

Winter leaves a mat of dead vines and dried pods

Although native to North America, Echinocystis lobata is in fact an invasive species in Europe, where it was first introduced as an ornamental garden plant (always the same sad story). This serves as a reminder that not all invasive species move from the Old World (Europe, Asia and Africa) toward the New World (the Americas). Poison ivy plagues England and parts of mainland Europe because back in the 1600s people thought it was pretty!

And not all invasive species are plants. Some of the most damaging to have made the crossing from North America to Europe are grey squirrels, raccoons, mink, and lobster. The mammal introductions were deliberate - either as pets or an attempt to develop locally grown animals for the fur trade. American lobsters may have been escapees from seawater holding pens for the food trade or deliberate releases by people who bought live lobsters air-shipped to Europe, and then found themselves unwilling to immerse their purchases in boiling water. 

The American bullfrog is considered one of the world's worst invasive species in Europe and elsewhere. Introduced as a food source (bullfrog farms), these frogs escaped into the wild where they out-complete native frogs by laying massive numbers of eggs and eating just about every living thing they can fit into their mouths (including native frogs).