See September 2012 for column on four invasive plant species.
|Immature seed pod next to male flowers|
The species name is Echinocystis lobata. It is a fast-growing annual propagated by seeds. This vine can blanket low plants or tendril its way 15-20 feet up trees. During July and August the slender vines display white flowers, followed by the development of seed pods that superficially resemble a small, spiky cucumber. Once the seed pods mature they dry out and disperse from the bottom several large black seeds the size of pumpkin seeds. Echinocystis dies with the first frosts of fall.
|Swathe of wild cucumber next to Assabet River Rail Trail|
|Lobate leaves, tendrils, and vertical spikes of male flowers, Echinocystis|
The name 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 southern California, but confusingly, there are related plants in California and Baja California (Mexico) that also go by the common name wild cucumber.
The latter are in the family Marah. These are also fast-growing vines with tendrils and seed pods that superficially resemble a spiky cucumber, but Marah are perennials, each year's new growth sprouting from a huge tuberous root that can weigh more than 100 pounds.
|Maturing wild cucumber seed pods|
|Spiked seed pods dry from the bottom up, then peel|
apart. The mature seeds (dark color) fall to the ground.
The dry, brown pods remain attached to the vine.
And not all invasive species are plants. Some of the most damaging to have made the crossing from North America to
|Dead wild cucumber vines, with seed pods|
These photos taken along a 1200 foot long section of rail trail in Maynard, MA. What's noteworthy is how fast the wild cucumber went from not present at all to overwhelming other growth. Within five years it went from a plant or two to a major nuisance in the areas of partial to full sunlight. It does not do well in deep shade.
By spring, last year's vines will have rotted under winter's snow. First plants to appear on this part of the trailside include pokeweed and Japanese knotweed. The wild cucumber vines don't really take over until July
UPDATE: Rail Trail construction in Maynard in 2017 completely destroyed the wild cucumber patch on that section north of Summer Street.