Foraging: identifying creeping cucumber, edible wild fruit

Latin name: Melothria pendula
Common name: Creeping cucumber
Season: Summer
Edible: Unripe fruit ONLY
Flavor: Good
Medicinal value: Unknown, but see notes below
Nutritional value: Carbohydrates, fiber, vitamin C and a surprising amount of protein

Identification difficulty: Beginner

Note on edibility: Only unripe fruits, which are light to medium green and hard should be eaten. Once even slightly soft or dark green, these fruits become dangerous laxatives. Some people, myself included, are highly sensitive to the laxative effects of this plant, even when the fruit is very unripe. I recommend only trying 1-3 at first, until you discover how you react. 

This charming little viny plant is Melothria pendula, commonly known as the creeping cucumber or the Guadalupe cucumber. The common names come from the similar appearance of the plant to cultivated cucumbers, although in miniature. Despite the names and the similar appearance, creeping cucumber is only distantly related to its cultivated cousins; they are both in the Cucurbitaceae family. 

The Cucurbitaceae family, or the gourd family, contains most melons, gourds, squashes and cucumbers. Cultivated cucumbers are part of the Benincaseae tribe (which also contains watermelons) and the Cucumis genus, but creeping cucumbers are not part of that tribe. 

What creeping cucumber does have in common with cucumbers and the white rind of watermelons is the taste. 

Creeping cucumber flower and young leaves

Creeping cucumber range

In the United States, creeping cucumber is found in the southeast states only, from Virginia south to Florida, and west as far as Kansas, Oklahoma and Texas. In rare occurrences it has been found in Pennsylvania, though be sure to really check your identification that far north. 

Outside of the USA, this plant can be found in Mexico, Central America, including the islands of the West Indies, and parts of South America. I am not sure how far south it extends. It has also been found tropical areas of the far east, such as Malaysia, Sumatra, the Philippines, and Bali. It is likely introduced to those areas. 

As always, this post is intended for readers in the United States, and I cannot account for potential look-a-likes in other countries, as I would not be aware of them. 

Creeping cucumber season

In the southern USA, you may begin to find fruit as early as June, and fruiting will continue throughout the summer, until the days start to shorten in September. In the northern part of the plant's range, you can't expect fruit before July. 

Creeping cucumber identification

Creeping cucumber leaves

Creeping cucumber stem, vine and leaf features 

Creeping cucumber is a tiny vine, only about 3-4mm in diameter, though the fruit-bearing tendrils will be thinner. The image to the right gives you a pretty good idea of the thickness of the vines as compared to my fingers.

As shown in the photo above, the thin leaves are palmate, which is to say that the leaf veins all come from a single point where they connect to the stem, like the fronds on a palm tree connect to the trunk.

They have 3 lobes when young, but 5 when mature, though 2 lobes will always be rather subtle. I have numbered them to make them easier to see in the photo above. 

As creeping cucumber is a vine, it can't support its own weight and creep over woody plants and even young trees, often forming dense mats. (See below.) Plants covered this way will die. 

The vine attaches to other plants via delicate tendrils shown here. The leaves, stems, vines and tendrils are all poisonous and should not be eaten. 

Creeping cucumber tendrils

A dense mat of creeping cucumber vines, covering other plants and underbrush.

Flowers 

Creeping cucumber flowers are bright yellow and have 5 petals. Each petal is notched at the end.

The flowers are dainty, around 7mm in diameter, or slightly larger than a pencil eraser. 

The flowers hang off pendules (from which the plant gets the second part of its Latin name: pendula), at the node where two opposite leaves meet on the vine. This means that the flowers, and the fruit they turn into, will often be hidden under the leaves. 

This unripe fruit is at the perfect stage for eating

Fruit 

ONLY UNRIPE FRUIT SHOULD BE EATEN.

Unripe fruit is light green, speckled, and firm or hard. 

Creeping cucumber fruits are ovate or occasionally  teardrop shaped. 

They are small, not more than an inch in length and half to 3/4 of an inch in diameter. They can be smaller, around the size of a jelly bean. 

Some say they resemble tiny watermelons, though I think they look closer to a small cousa squash. 

The one shown to the right is at the perfect stage for eating. Once they darken and soften, the spots will fade and the insides will start to become gelatinous (see below). They will eventually become near-black. 

These fruits are too mature and will have
a dangerous laxative effect if consumed

Ripe fruits are powerful laxatives, eating them will result in the urgent need to painfully defecate and can potentially lead to dangerous dehydration and even muscle spasms. 

Eating creeping cucumber

Creeping cucumbers are fun to pick and are famously popular with young children who grow up in the states where they are native. 

The unripe, light green fruits taste similar to cucumbers, though I personally think they are closer to the white parts of watermelon rind. They are crisp and slightly juicy, and their best application is probably tossed into a salad. If you find a large amount you could also pickle them. 

Creeping cucumber nutrition

Creeping cucumber is generally ignored by American publications, but has been analyzed by Mexican authorities. Unfortunately, these publications are in Spanish, which I can't read or speak. 

However, according to "Green Dean", famous forager and author of the Eat the Weeds website, who had a friend translate the study, the caloric nature of unripe fruits are made up of 56.8% carbohyrdate, 16.30% fiber, and a surprising 12.6% protein. They are also good sources of vitamins and minerals, though which ones specifically aren't mentioned in the original publication I found, at least not the part that has been translated into English. It is possible they are similar to cultivated cucumbers, which means they would primarily have vitamin C and potassium. 

Unfortunately, the small size of these fruits makes their nutritional value rather limited, unless they could be cultivated to be much larger. 

Medicinal applications - don't

Despite the ripe fruit being a powerful laxative, it is important that you do not attempt to use creeping cucumber medicinally. The native peoples of the Americas were well-aware of this plant and yet no record of it being used medicinally has been found. This is likely due to how very powerful it is. It would be difficult to find a way to safely use this plant--and attempts could result in dangerous cramping and dehydration. 

Creeping cucumber look-a-likes

There really are no potential look-a-likes for creeping cucumber fruits in the USA, making this plant a very safe one to identify for consumption. But it is possible to confuse the pre-fruiting plant with some  other common vines. 

English ivy, poisonous

English ivy has leaves that are similar in shape and size to creeping cucumber, but are much thicker and  shinier. When mature, leaves are deeply lobed and have mottled colors . The vine is also thicker and woody. English ivy fruits are dark purple-indigo rather than green-black, and grow in clusters on a stalk, rather than hanging down on a vine. 

Members of the genus Ampelopsis, mildly poisonous 

The genus Ampelopsis contains many vining species which are quite widespread throughout the USA, including the native heart-leaf peppervine (A. cordata) and the invasive porcelain berry, (A. glandulosa). Ampelopsis vines are thicker than creeping cucumbers, the leaves are larger and thicker, and the fruits grow in clusters, not individually. 

Additionally, the fruits are generally bright colors, including magenta and blue, but never green nor black.