Trichocereus bridgesii monstrose TBM (Penis Cactus)

Description

Type: Unrooted, callused cutting, ungrafted · Size: 8 to 10 segments · 8 available, sold individually

Penis cactus is the common name of Trichocereus bridgesii monstrose, or TBM, and this listing is for the short form, Type B, as an unrooted cutting of 8 to 10 segments. We have eight for sale. The photo shows a representative clump on our mother plant; your cutting comes from the same clone with the same segment count, ungrafted.

What the penis cactus is

TBM is a monstrose cultivar of the Bolivian torch, the cactus sold as Trichocereus bridgesii. Instead of growing as a tall ribbed column, each stem grows a short segment, stops, and buds a new one, so the plant builds a knobbly cluster of rounded, blue-green to deep green pieces. The upper part of each segment is smooth and nearly spineless, and the lower part carries the spines. That growth habit, and the shape of the segments, earned it the penis cactus name.

It is a conversation piece in any collection, and an easy one to keep once you know its one weakness.

Short form and long form

Two TBM clones circulate. Sacred Succulents began calling the long, columnar form clone A and the short form clone B, and most growers follow that labeling, though the letters can swap from one region to another. The short form is by far the more common of the two. Its segments stop at roughly three to six inches, it carries two to five ribs, and its spines are strong and easy to see even on small plants. The columnar long form is much rarer.

Kew POWO accepts Echinopsis lageniformis as the name of the species, and our Echinopsis lageniformis species page covers the Bolivian torch and its monstrose form in detail.

How we grow it

At rarecactus.com we grow our Trichocereus mother plants, TBM included, outdoors in full sun in Orange County, California, in a 50/50 soil mix of organic and inorganic material. The monstrose bridgesii rots more easily than the normal plant when it stays wet, so we water it on a strict soak-and-dry rhythm and never leave it sitting in damp mix. Each cutting comes off our own plant of the clone.

When your penis cactus cutting arrives

Check the face where it was cut from the mother clump. Once that surface is dry and hard, the cutting is ready to root. If it still looks fresh, leave it in bright shade for a few more days.

Let it root in a dry area: stand the cluster upright on its cut base in bright indirect light and give it no water until roots form. That usually takes a few weeks in warm weather. Then pot it in a 50/50 soil mix of organic and inorganic material so the segments sit just above the surface, water lightly, let the mix dry right out between waterings, and bring the plant into stronger sun gradually.

Of everything in this collection, TBM is the one to underwater rather than overwater.

The knobbly habit looks best in a wide, shallow-to-medium pot where the cluster can spread sideways, and a top dressing of coarse grit keeps the lowest segments dry. A cutting of 8 to 10 segments is already a small plant with a shape of its own, so it reads as a finished specimen on a bench from the first season.

Provenance and legality

CITES lists Trichocereus, like most cacti, on Appendix II, and this is cultivated stock propagated in the United States. Bridgesii and the other San Pedro relatives are legal to own as ornamentals in all fifty states, and our legality guide cites the statute state by state. More clones are in the Bolivian torch cactus for sale collection, and the Echinopsis encyclopedia hub covers the genus.