Cardiospermum halicacabum -- common names: Balloon vine, Love in a puff, Heartseed, or Heartseed vine. This fast growing vine will reach up to 10 feet in one season. It has tendrils which grab and wrap around tripod, trellis, or pergola to support its growth. The foliage is ferny in appearance and it produces small white flowers reminiscent of those of Baby’s Breath (Gypsophila muralis) and following the flowers seed pods form which contain the unique seeds.
Each seed pod is a three-sided green balloon that turns brown and stays inflated. When squeezed, it "pops" and you find up to 3 pea-sized black seeds inside having a perfect cream-colored heart at the place where it was attached to the pod. This is where the scientific name Cardiospermum comes from meaning Heart (cardio) seed (spermum).
Love-in-a-Puff should be treated as a frost tender annual. Plant seeds in full sun in moist, but well drained soil. The vine is said to become a vigorous pest if left on it's own to reseed in certain southern growing zones (Alabama, Arkansas, South Carolina and Texas consider it a noxious pest weed -- Source: http://plants.usda.gov/java/profile?symbol=caha13).