Sunday, September 4, 2022

A Zucchini is Not a Cucumber 

Cucumbers are a part of any summer vegetable garden. And from salads and dips to sandwiches and smoothies, crunchy, refreshing, water-rich cucumbers are an indispensable part of any summer diet, as well.

I suppose, much the same can be said for zucchinis. And, given their similar appearance, it’s easy to see how cucumbers and zucchinis can sometimes be mistaken for one another. They’re alike in shape and color and belong to the same family of plants (Cucurbitaceae, the gourd family). But they’re of different genera (Cucumis and Cucurbita, respectively) and, actually, quite unalike.

Both are vining plants (although there are some newer cultivars that are bush varieties) but unlike cucumbers, zucchini aren’t natural climbers. Zucchini plants do produce small vining tendrils along their stems, but those tendrils can’t support the weight of mature fruit. (Despite the fact that they’re commonly used as vegetables, both zucchinis and cucumbers are botanical fruits.)

The tendrils on cucumber plants, on the other hand, are made up of highly-specialized cells, which react chemically and then electrically to contact with solid objects (much like our sense of touch). When a tendril contacts (or feels) a solid object, it will slowly and tightly wrap around it, which allows the plant to literally lift itself up, in order to gain greater exposure to sunlight. This behavior was first noted by the renowned biologist, Charles Darwin.

Another difference; female zucchini blossoms are edible. Cucumber blossoms are not.

 

Is a Cucumber a Melon? 

If you were shown a cucumber and a melon, you’d easily be able to tell the difference. Nonetheless, the two fruits are more-closely related than cucumbers and zucchinis. Cucumbers are Cucumis sativus. Melons are Cucumis melo. (Watermelons; Citrullus lanatus; are an exception.)

And they have similarities. Both like full sun. Their seeds are very-much alike. And it can be difficult to tell young seedlings apart. Moreover, both are low in sugar and calories, and high in fiber.

In order to make fresh crosses, the pollen from a male cucumber flower is capped around a female cucumber flower inside a greenhouse at Cornell University. Photo credit: Cornell CALS School of Integrative Plant Science.

What About Cucamelons? 

A cucamelon looks like an itty-bitty watermelon.  They’re sometimes called mouse melons. And I’ve heard it said they taste like cucumber and lime, or a slightly sour cucumber.

They’re entirely green inside. And can be eaten right off the vine. You don’t have to peel them, like you would a cucumber. And you can toss them into salads, like you would grape tomatoes; either whole or sliced.

To the best of my knowledge, cucamelons are not a hybrid or genetically modified. They’re native to Central America, where they were eaten by the Aztecs. Somehow, they’ve remained a secret until recently.

 

Why are some Cucumbers Bitter? 

Bitterness in cucumbers is caused by a natural, organic compound, known as cucurbitacin. The compound is always present, but it’s generally confined to the leaves and stems and is a natural defense system; intended to make the plant less-appealing to insects and herbivores.

Cucurbitacin usually doesn’t enter the fruit. But when it does, any bitterness is typically concentrated in the stem end of the cucumber and sometimes in the area right under the skin.

There’s disagreement about what causes the bitterness to progress into the fruits, but most vegetable scientists believe that environmental stress, while the cucumbers are growing (e.g. uneven watering, lack of water, temperature fluctuations), affects cucurbitacin levels.

Freshly-picked cucumbers. Photo credit: Millie Davenport, Clemson University Extension.

Why Do Cucumbers Make You Burp? 

Burping is a natural process; your body releasing excess air from your upper digestive tract. And after eating cucumbers, sensitive individuals may experience burping or other gastrointestinal discomfort. This is widely believed to be caused by cucurbitacin. And for that reason, it’s recommended that you don’t eat bitter-tasting cucumbers.

When ingested in high quantities, cucurbitacin can, in fact, be toxic. But the domestic varieties of cucumbers that we consume contain only small amounts of cucurbitacin in their fruits.

 

English / Burpless Cucumbers 

The English cucumber; also known as the seedless, burpless, European, or greenhouse cucumber; is the result of decades of efforts to breed a cucumber that’s easier to eat than other cucumbers. While most standard cucumber varieties possess a tough skin, the English cucumber has been specifically bred to be thin-skinned.

In addition, English cucumbers are parthenocarpic, meaning they’re able to develop fruit without fertilization, so their seeds never fully develop, almost eliminating the seedy interior found in other cucumber varieties. And they’ve been hybridized to contain lower levels of cucurbitacin. As a result, these cultivars yield cucumbers that are sweeter-tasting and, supposedly, easier to digest than traditional cucumber varieties. Nonetheless, it’s important to recognize that cucumbers affect every person differently.

 

Squirting Cucumbers 

While the squirting cucumber (Ecballium elaterium) is a relative of the edible cucumber, squirting cucumber plants contain toxic levels of cucurbitacin. All parts of the plant can be fatal, if ingested.
The squirting cucumber is so-called because of its distinctive method of seed dispersal. When ripe, the fruits snap off of their stems and forcibly eject their mucilage-covered seeds in an explosive stream.

Encyclopaedia Britannica has a short, online video showing this unique adaptation. It can be seen by visiting britannica.com/video/192988/seed-dispersal-squirting-cucumber

The plant is native to the Mediterranean region, but grown as a curiosity in many places. It cannot be grown here however, because squirting cucumbers are hardy only in USDA zones 8 through 11.

 

Photo at top: Cucamelons. Photo credit: University of British Columbia Botanical Garden.

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Richard Gast is a retired Extension Program Educator and has been contracted by Cornell Cooperative Extension Franklin County to continue his informative and thought provoking articles.




One Response

  1. Very Interesting…Thanks…Peace

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