The subspecies 'thornberi' has thicker stems at 1 inch wide and tapered at the base. The soft and hairy radial spines are not a distincti...Read Moreon.
The subspecies 'yaquensis' has more fragile stems at 0.6 inches thick with the soft and hairy radial spines being minute.
The subspecies 'thornberi' has thicker stems at 1 inch wide and tapered at the base. The soft and hairy radial spines are not a distincti...Read More