Trichocereus bridgesii f. monstruosus

Dry Bolivian habitats of the species

This unusual form is propagated from cuttings. It has no separate wild range. Its species, botanically accepted as Echinopsis lageniformis and long grown as Trichocereus bridgesii, is native to Bolivia and grows as a succulent tree in desert and dry shrubland.

Strong sun, dry air, sparse rainfall and marked temperature changes shape the species’ water-storing columns. At home, give it very bright light, a gritty cactus mix and long gaps between waterings. The irregular growth comes from a mutation maintained through vegetative propagation.

Plant care for Trichocereus bridgesii f. monstruosus

Strong light for dense knuckled growth

Place in the brightest position available and introduce direct sun gradually. Healthy growth remains irregular and firm; unusually long pale sections indicate that the plant needs more light.

Water only with active growth

Water deeply during warm active growth, then let the mix dry throughout. Water much less in cool or dim conditions. The fleshy stems store water, and the resting roots take up very little.

A stable pot with a coarse cactus mix

Use a coarse, fast-draining cactus mix in a container with a clear drainage hole. Choose a stable pot with room for offsets and no large volume of slow-drying compost.

Warm growth and a bright dry winter

Most new growth appears during warm summer conditions. A bright, dry and protected winter rest limits weak growth. Use a small amount of low-nitrogen cactus fertiliser only when the plant is growing and taking up water.

Troubleshooting Trichocereus bridgesii f. monstruosus

Knuckles, constrictions and broken rib patterns

These irregular shapes define the monstrose form and remain firm during healthy growth. Concern begins when a section also becomes translucent, dark or soft.

A new knuckle elongates and turns pale

Insufficient light produces stretched growth that differs from the dense irregular form. Increase exposure gradually; later growth can become firmer. The elongated section remains visible.

A constriction or the stem base becomes soft

This is a rot warning, especially after watering in cool conditions. Stop watering, inspect the roots and cut back only to completely firm, clean tissue.

Pale corky patches form after stronger sun

Abrupt direct exposure can burn the irregular raised surfaces. Acclimatise over several weeks and keep the scarred area dry as it hardens.

White pests collect in folds or at the root collar

Inspect the constrictions, areoles and base for mealybugs or scale. Isolate the cactus and repeat control without forcing apart the knuckled stems.

Trichocereus bridgesii f. monstruosus is toxic to people and pets

• Keep this plant away from children, cats and dogs, and handle its spines carefully.
• The plant can contain mescaline and related alkaloids, while its spines can puncture skin, eyes, mouths or paws.
• Swallowing plant material may cause vomiting, agitation, tremors or unusual behaviour. Contact a veterinarian or medical professional immediately after ingestion or a serious injury.

How did the name change from Trichocereus bridgesii to Echinopsis lageniformis?

Trichocereus combines Greek for “hair” with Cereus, a traditional name for columnar cacti. Bridgesii honours botanist Thomas Bridges.

Vincenzo Riccobono established the genus Trichocereus in 1909 in Bollettino del Reale Orto Botanico di Palermo, volume 8, page 236.

Joseph Franz Maria Anton Hubert Ignatz Fürst zu Salm-Reifferscheid-Dyck first described it as Cereus bridgesii in 1850 in Cacteae in Horto Dyckensi Cultae, 1849, page 208. Nathaniel Lord Britton and Joseph Nelson Rose later placed it in Trichocereus as Trichocereus bridgesii in 1920 in The Cactaceae, volume 2, page 134.

Kew’s World Checklist treats Trichocereus bridgesii as a synonym of Echinopsis lageniformis. Heimo Friedrich and Gordon Douglas Rowley placed the species in Echinopsis as Echinopsis lageniformis in 1974 in Bulletin of the International Organization for Succulent Plant Study, volume 3, page 96.