Spines less than 1 year old are generally puberulent. The scarlet flowers are diurnal, remaining open for 2 or 3 days. In addition, the closed canopy of dense mounds of hedgehog cactus maintains surface and internal stem temperatures within the mound below ambient temperatures during daylight hours. Temperatures within the mound then increase gradually for several hours after the sun sets, allowing hedgehog cactus to survive low night temperatures. No other regeneration information was found in the literature.
Hedgehog cactus is found on a variety of sites and within a wide elevational range.
E. t. var. E. t. var. E. t. var. E. t. var. E. t. var.