A stowaway seed (or, more likely a forgot-I-put-it-in-there seed) sprouted in one of the big clay pots along the shady north side of my house earlier this summer.
Out of my usual context for the plant -- vigorously climbing up the side of the McMillan Greenhouse in full sun -- I didn't recognize those first leaves and nearly pulled it. Curiosity nearly always gets the best of me, though, so I waited to see what would happen. When it started to get tendrils and tiny white flowers, I finally caught on -- Love-in-a-puff vine!
As summer started to wind down, light green balloons began to form on the plant. (If you pinch these, they'll pop!) Once the balloons dry out and turn brown, you can tear them open and harvest the seeds.
Love-in-a-Puff (Cardiospermum halicacabum) is also known as heart seed, because that's exactly what you get inside the papery puffs. I'm not very good at taking pictures with one hand and propping a roly-poly seed in the other, but maybe you can see the distinct heart on each seed; they usually look so perfect you would think they're painted on.
Besides the interesting seeds and pods, the vine attracts several butterflies as both a nectar and host plant. Check the link below* for more interesting info about that. It has also been used medicinally for itching and rashes as well as a number of other things. I just enjoy the ferny leaves and fast growth of a vine that is willing to put up with nearly anything from the gardener!
Notes: Love-in-a-puff is an annual, so don't forget to save the seeds when they form. And, if you live in zones 8 - 10, plant it where you can keep a close watch on it because it will be an invasive pest. It will grow (safely!) indoors in a sunny window. Seeds are available from several online sellers and seed swap sites.
*Cardiospermum halicacabum - Wearing Your Heart on a Seed on Valentine's Day and Beyond by Arlene Marturano