Physalis philadelphica

The tomatillo (Physalis philadelphica and Physalis ixocarpa), also known as the Mexican husk tomato, is a plant of the nightshade family bearing small, spherical, and green or green-purple fruit. Tomatillos originated in Mexico and were cultivated in the pre-Columbian era. A staple of Mexican cuisine, they are eaten raw and cooked in a variety of dishes, particularly salsa verde. The tomatillo is a perennial plant, but is generally grown for agriculture each year as if it were an annual....read more on Wikipedia.