Wild Cucumber (Echinocystis lobata), fam. Cucurbitaceae.
A weed, introduced to us from other countries, has occupied the wetland along the river, near the transmission line. The vines creep over all the trees there, hanging down the prickly "cucumbers" with black seeds inside. Young fruits are considered edible (but this is doubtful).
This plant should not be confused with "Squirting cucumber", which has more studied medicinal and poisonous properties, and its fruits explode, shooting out the seeds - it does not grow in Kyiv. Unlike it, the wild cucumber seeds simply and quietly fall out of drying fruits. In the city, wild cucumbers occur in the case of fresh humus-rich soil delivery, contaminated with its seeds.