Tomatillos are part of the nightshade (Solanaceae) family, along with tomatoes and peppers. The leaves look a bit like those of eggplant, another nightshade plant. Nightshade plants are grouped together because they each produce the same particular type of flower.
The fruit’s very name is a misnomer. “Tomatillo” means “little tomato” in Spanish, and while they are distantly related, the tomatillo is very definitely not a tomato.
Nevertheless, nicknames linking the two tasty fruits abound, with the tomatillo also being referred to as “tomate verde” (green tomato) and “husk tomato.”
Originating in Mexico and Central America, this citrusy plant has been an important food crop for millennia, though the plant has been around for even longer. In fact, in early 2017, scientists writing for the journal “Science” reported on their discovery and analysis of a 52-million-year-old fossilized tomatillo found in the Patagonia region of Argentina.
Tomatillo plants grow wild throughout their native regions, and some wild varieties in parts of the midwestern United States, where they — despite their edibility — are derisively referred to as weeds and are considered invasive.
Historical records show that numerous North American native tribes used these wild fruits (Physalis longifolia) to treat headache and stomachache, according to the Native Medicinal Research Program at the University of Kansas.
Prized for their unusual flavor and bright green color, these tangy fruits are now cultivated and enjoyed around the world. They can be eaten raw but most commonly are cooked.
Source: https://gardenerspath.com/plants/vegetables/tomatillos/