The Biology of Wild Cucumbers
| By Johnny Caryopsis | (Click links for more images.) |
Description
The wild cucumber is an annual plant; that is, it grows from seed each spring and dies in the fall. It produces no woody tissue. It is a climbing vine and has long twisted tendrils which entwine the leaves, stems or branches of other plants. It is usually found sprawling over the low branches of trees or shrubs next to waterways, but can grow as a dense mat on open ground, as well. The leaves, up to 14 cm across, are thin, light green in colour, with 3-7 (usually 3 or 5) large pointed lobes; essentially a "maple-leaf" shape, as in, on our penny (except those are gone now!), not our Manitoba maple leaf. Its male flowers, more conspicuous than the small female flowers, are greenish-white with 6 petals. They bloom in late July and into August. The characteristic "cucumbers", up to 6 cm long, green in colour and covered in soft bristles, form by late August or into early September. They are a form of fruit called a "pepo", a large fleshy berry with a thick skin.
Name
Wild Cucumber (Echinocystis lobata) is a member of the cucumber or gourd family, the Cucurbitaceae. Included in this family are such familiar plants as domestic cucumbers (Cucumis sativus), squashes and pumpkins (Genus: Cucurbita), and other melons (Genus: Cucumis). Its most usual common name is drawn from the resemblance of its fruit to that of the domestic cucumber. Balsam-apple is another common name for Wild Cucumber. It's scientific name breaks down as follows:
Echinocystis:
Echino - from the Greek "echinos", a hedge-hog; the prefix "echin-" always means spiky, prickly or "hedge-hog-like". Cystis is also Greek, referring to a bladder or pouch. So, Echinocystis refers to a spiky bladder, an apt and logical reference to the wild cucumber.
lobata:
From the Greek, "lobos" - a lobe, capsule or pod. This may also refer to the large cucumbers, that are the most significant feature of this plant or it may be referring to the distinctly lobed internal structure of the cucumbers.
Habitat and Range
The habitat of Wild Cucumbers is quite variable, but they are most often found where water is readily available. Waterways that experience spring flooding, which provides both moisture and fresh deposits of silt, along with thick shrubs or trees to grow upon, seems to be ideal habitat for Wild Cucumbers. However, being annuals, they will grow wherever they get a chance. While the large seeds tend to fall to the ground below the parent plants, they could be carried around or cached by birds or mammals and, if uneaten, could end up growing in odd locations.
This species occurs across southern Canada and southward throughout most of the United. It is very common in southern Manitoba, but likely doesn't extend into the boreal forest region.
Life Cycle
Seeds of Wild Cucumber germinate in the spring and the young vines grow rapidly. The vines reach toward the sunlight, using the stems and branches of other plants as supports. The flowers of wild cucumber are unisexual; that is, there are separate male and female flowers at different locations on each plant. As the male and female flowers are found on each individual plant it is still considered to be monecious ("in the same house"). The male flowers are held in small panicles (a panicle is a branched cluster of flowers) and the much smaller female flowers are located in the leaf axils (where the leave stalk, or petiole, meets the stem). Wild Cucumber flowers are in bloom in early to mid-August. The cucumbers, which nearly always contain 4 large seeds (1-1.5 cm long), develop from the female flowers by the end of August and into September. By the time the cucumbers are ripe the entire plant is beginning to die. The cucumbers are the last part of the plant to dry out and die. They open at the bottom, and the large seeds fall out onto the ground, where they will lie until the following spring. By growing towards the light on shrubs and trees along waterways the wild cucumber keeps dropping its seeds in the most advantageous spot for next year's plants to start off. A single plant may grow 20 m or more from where its originating seed first germinated, so its progeny can spread quite a distance over several generations.
How tendrils work!
Tendrils are modified leaves, or stems in some cases, that serve to anchor and support climbing vines. They respond to touch. When a tendril contacts an object, cells touching the object shorten while those on the opposite side elongate. The net effect is to curl the tendril around the potential support. Some tendrils can respond to contact quite rapidly, in only a few minutes. Once the tendril end has been anchored by wrapping itself around the support, the rest of the tendril coils up, spring-like, drawing the vine stem closer to the support. The tendril will continue to grow spirally and encircle the support object by maintaining differential growth rates between the cells touching the support and those not touching it.
Uses
In addition to its decorative and novelty uses in gardening and dried arrangements, Wild Cucumber is thought to have some medicinal or herbal values. Aboriginal peoples used teas made from its roots for stomach or kidney ailments. It was, apparently, added to love potions and the roots were used in poultices for headaches. Its dense growth form may offer shelter to various wildlife species, and its large seeds certainly provide birds and small mammals with a source of food. The large seeds are often interestingly patterned and can be used in artwork or as decorations. If you want to collect some seeds, collect the cucumbers while they are green and the ends are still closed. Then let them dry, and the seeds will fall out.
Thanks for learning about Wild Cucumbers! Bye for now!
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Acknowledgments
Some of the information found in this article was drawn from the following sources:
The Peterson Field Guide Series: A Field Guide to Medicinal Plants. Eastern and Central North America. By S. Foster and J. Duke. 1990. Houghton Mifflin Co., Boston.Budd's Flora of the Canadian Prairie Provinces. Revised by J. Looman and K. F. Best. 1987. Research Branch, Agriculture Canada Publication 1662.
Biology of Plants, 2nd Edition. By P. Raven, R. Evert and H. Curtis. 1976. Worth Publishers Inc.
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