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.
Trichomonas tenax Trichomonas tenax, or oral trichomonas, is a species of trichomonas commonly found in the oral cavity of humans, dogs and cats. Routine hygiene is generally not sufficient to eliminate the parasite, hence its Latin name, meaning "tenacious". The parasite is frequently located in periodontal infections, affecting more than 50% of the population in some areas, but . Trichomonas tenax is generally not found on the gums of healthy patients. It is known to play a pathonogenic role in necrotizing ulcerative gingivitis and necrotizing ulcerative periodontitis, worsening preexisting periodontal disease. This parasite is also implicated in some chronic lung diseases; in such cases, removal of the parasite is sufficient to allow recovery (Mussaev 1976).