Vine Weeds of Missouri
Balloonvine takes its name from its inflated, three-sided fruit, which resembles a hot-air balloon. The seed leaves, or cotyledons, of balloonvine are rectangular, but subsequent leaves are divided into three lobes and are alternate on the vine. The plant has tendrils, a distinctly ridged stem and small, white flowers that have four petals. Balloonvine seeds have a distinctive, seamed appearance, like a baseball or tennis ball, one side white and the other black. Balloonvine poses a problem in fields where the soybean crop is produced for seed. Balloonvine seeds, essentially the same size and weight as soybeans, are difficult to clean out of the harvested crop.
Balloonvine was probably introduced as an ornamental vine. Its distribution in Missouri is restricted to the eastern part of the state.