Penis Cactus (Echinopsis lageniformis f. monstrose) is one of the most talked-about novelty cacti in cultivation — a clumping cactus made up of short, blunt, finger-like stem sections that are smooth and almost spineless on their upper parts. Its light blue-green stems branch eagerly at the base, slowly forming a sculptural little mound that never fails to start a conversation.

Beyond the humour, this is a genuinely interesting collector's cactus: slow-growing and easy to keep, with honey-coloured spines only near the base of each section. Mature plants can surprise you with large, white, night-opening trumpet flowers, though flowering is rare in this monstrose form and most growers grow it for its unique sculptural shape.

Plant Information

Botanical Name
Echinopsis lageniformis f. monstrose

Common Name
Penis Cactus

Stem Colour
Light glaucous green — short, blunt, cylindrical sections, smooth and mostly spineless above, with a few honey-coloured spines near the base

Form
Low, clumping — stems branch avidly from the base

Flowers
Large, white, fragrant trumpet flowers that open at night — rare in this monstrose form

Mature Size
Stem sections 10–20cm tall, forming a spreading clump

Sunlight
Full sun to light afternoon shade in extreme heat

Watering
Soak and dry — water thoroughly then allow the soil to dry completely; keep almost dry in winter and avoid water settling between the stem sections

Soil
Very well-draining cactus mix with plenty of inorganic material

Frost Tolerance
Frost tender — keep above 5–10°C and never let it freeze

Pot Size
Supplied in a 12cm pot

Important Notes

• Rot-prone creases: Water the soil, not the plant — water lodging between the stem sections is the main cause of rot
• Slow grower: Grows markedly more slowly than its columnar parent species
• Rare flowers: White night-opening blooms are possible on mature plants but uncommon
• Handle with care: A few honey-coloured spines sit near the base of each section
• Delivery: Delivered across South Africa — please ensure someone is available to receive your plant

Perfect for succulent collectors, container gardens, and decorative plant displays.