This species is rarely seen but would be an excellent addition to the vine selection in the south of Finland. Without support, the threewingnut grows as a spreading bush, but given a tree to climb it can reach several metres, looking for light.
Threewingnut flowers in July. Although the individual flowers are small, there are so many flower corymbs that from a distance the vine looks decorated with white lace. The fruits have three wings, as the name suggests, which in autumn take on a strong red colour.
The species has been reported to sometimes produce root suckers, though none has been seen in Mustila. If there is free space for them they can be allowed to grow, when the shoots use whatever support is available, as in nature. The best specimen at Mustila is doing its best to completely cover one of the porches of the office building.
Threewingnut is tender to autumn frosts, which can blacken the leaves and kill off the tips of the season’s growth. The pale brown fruit, however, persist until blown off by winter winds.