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 of the same name. 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. Tomatillos are a key ingredient in fresh and cooked Mexican and Central-American green sauces. The green color and tart flavor are the main culinary contributions of the fruit. Purple and red-ripening cultivars often have a slight sweetness, unlike the green- and yellow-ripening cultivars, so generally are used in jams and preserves. Like their close relative the Cape gooseberry, tomatillos have a high pectin content. Another characteristic is that they tend to have a varying degree of a sappy, sticky coating, mostly when used on the green side out of the husk. (Source: Wikipedia.org, CC BY-SA)