Plants used by Indians tend to be weedy, or to grow in diverse habitats. In effect, they are widespread across habitats, rather than just geographically. This one was growing on a freeway margin. Tomatillo is native to Mexico. It may well have moved north of our border in pre-Columbian times. It was used as food and medicinally by the Kumeyaay tribe of southern California. It was a very important plant to the Aztec and Mayan peoples. Tomatillos were more widely used than tomatoes. It now pops up almost anywhere in the US, including my garden last year, and our supermarkets. Tomatillos are a key ingredient of green sauces in Mexican cuisine. They have now been found in AZ, CA, DE, HI, IA, ID, IL, IN, KS, KY, MA, MD, MI, MN, MO, MS, NC, NJ, NM, NY, OH, OK, OR, PA, TN, TX, VA, VT, WA, WI, WV, AB, MB, ON, and QC. Monroe Co MI, 8/4/11.