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 |
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 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 |
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).