How are Obregonia and  Trichodiadema different from each other?
Obregonia Obregonia, the artichoke cactus, is a genus of cacti with a single species, Obregonia denegrii. The species is endemic to the state of Tamaulipas in Mexico.
Trichilemmal carcinoma Trichilemmal carcinoma (also known as "tricholemmal carcinoma") is a cutaneous condition reported to arise on sun-exposed areas, most commonly the face and ears.