TBM cl. A long form
long form TBM cl. A, reverts available on occasion
Cl. A tends to grow long sections and has been grown in cactus collections for decades. First origin of this plant is unsure.
There are two forms of TBM that are most common - one produces short segments and the other produces long segments. At one point Sacred Succulents began referring to the long form as cl. A and the short form as cl. B. Sacred Succulents has also named a cl. C and cl. D. C and D tend to have a melted wax type growth rather than the distinct segment growth of A and B.