Reproducing only by seed.
Stems vine-like, much-branched, climbing over fences, shrubs and trees to a height of 5m or higher, soft and somewhat fleshy, lengthwise grooved, hairless or sometimes hairy at the nodes.
Bright green, long-stalked, usually 5-lobed, resembling the cultivated cucumber, the margin of each lobe smooth or with scattered slender teeth; the lobes deep and the petiole attached in the broadly rounded heart-shaped leaf base, each leaf usually paired with a long, curly, branching tendril on the opposite side of the stem at the same node.
Flowers with sexes separate, male flowers in long, showy, branching panicles from the axil of each leaf, their petals small, white or greenish-white with prominent yellow anthers but with no pistil or ovary; female flowers short-stalked, one in the axil of the tendril opposite the petiole of the leaf immediately below each cluster of male flowers; female flowers with no stamens but with a small, spherical, weakly spiny ovary below the 6 small, yellow-green petals; fruit fleshy, oblong 2.5-5cm long, weakly prickly, after maturity dying and opening at the blossom end, releasing 4 large, flat, brown to blackish mottled seeds; the dry empty seedpod hanging from the branch during fall and winter as a small spiny mesh bag. Flowers from July to late autumn.
Wild cucumber occurs throughout southern Ontario in river bottoms, meadows, edges of woods, fence lines and waste areas, usually in low moist areas, but occasionally in drier sites as well.
It is distinguished by its vine habit, its branched tendrils opposite the bright green leaves, its long clusters of male flowers, its female flowers borne singly and its large, fleshy, weakly spiny 4-seeded fruits, also borne singly.
A. Branch with cluster of male flowers and 1 female flower. B. Portion of branch with 1 fruit.
Wild cucumber fruit on plant.
Fleshy, prickly fruit of wild cucumber.
Fruit of wild cucumber.
Flat, "molted" seeds of wild cucumber
C. Young plant.
Wild cucumber cotyledon
Young plant. Photo taken in spring, Southwestern Ontario.
Vine-like plant, growing over trees.
Leaves of wild cucumber
Bright green leaf of wild cucumber
Branched tendrils of wild cucumber growing around tree branch.