Blue Balloon Flower
(Edible) This is a lovely and unique perennial. The blooms will expand like an inflated balloon until they burst open into a gorgeous blue star. Two-foot tall plants will set off tons of explosive little blooms late into the season when many flowers are spent. The roots are appreciated for having antimicrobial, antibacterial and other medicinal qualities. Roots are used in Asian food.
(Source: Baker Creek )