As with most kiwis, A. polygama is dioecious, bearing attractive small white male and female flowers on separate plants. Silver vine fruits are considerably smaller than those of the commercially available kiwi (A. deliciosa), have an ovoid to cylindrical shape, and mature bright orange rather than green. The fruits are quite edible, and both the fruit and leaves of silver vine have been used in traditional medicine.
It turns out that it’s not just humans who are fans of this vine. Many cats respond in a euphoric way (like a catnip high) to various parts of A. polygama. In 1939, longtime Arnold Arboretum plant propagator William Judd reported [pdf] that neighborhood cats had climbed into the greenhouse just to get at silver vine plants he was propagating! Recent research shows that the most alluring part to cats is dried fruit galls (fruits that had been infested by matatabi fruit gall midges [Pseudasphondylia matatabi], a pest of A. polygama), which are available whole or in ground-up form as “cat powder.” In an improptu test, the cats of several Arboretum staff members responded positively to fresh cut stem sections of silver vine. I’ve ordered some of the fruit gall powder for a follow-up test to be conducted soon.
Nancy Rose, editor of Arnoldia