Obregonia denegrii
Native range: Eastern Central Mexico
Known names: Obregonita, Obregona, Peyotillo, Artichoke Cactus
Hardiness: Best to keep above freezing
Mature Size: ~3" Tall, ~4" wide
Light: Full sun
Water: Drought tolerant but appreciates water during hotter seasons. Maybe every other week during summer, once a month in winter. 
Soil: Succulent mix, add sand. 
Dormancy Period: Winter
Pet-Safe: No
Plant Size: 2.5" pot
 
Obregonia denegrii are not fully desert-type cactus; they can be found in grassland and open forest areas of eastern Mexico. People [over] harvest these in the wild making them now illegal to collect. They are known to have the same affect on humans as Peyote cactus BUT DON'T YOU DARE TRY!. With this unmistakable water lily-like shape, this cactus is definitely a unique one!