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.
TBM A rarely flowers. For years it was thought that TBM A does not produce flowers at all. However since 2020 TBM A has been blooming each year at the Cactus Affinity nursery. Pacific Cactus is also known to have flowering TBM A cactus they have used to produce seeds.
