Euphorbia piscidermis, also known as “Fish Skin Euphorbia,” is native to Ethiopia. Its name ‘piscidermis’ comes from the Latin for ‘fish-skin’, reflecting its distinctive, intricate, scale-like surface. This unusual succulent is often grafted onto other Euphorbia species because it can be challenging to grow on its own roots.
Euphorbia piscidermis is a dwarf succulent with subspherical stems. These stems are densely covered with creamy-white, overlapping appendages, creating a unique “fish-scale” or “pinecone” texture. The plant typically grows as a solitary stem, reaching up to 5 inches tall and 3 inches in diameter. It is native to the dry, rocky, and exposed succulent scrublands of Ethiopia’s Ogaden region, where it benefits from bright sunlight. Its scaly texture is an adaptation to its arid native habitat, likely helping to reduce water loss.
Essential Care for Euphorbia piscidermis
Light Requirements
Euphorbia piscidermis thrives in bright light but needs protection from harsh, direct midday sun, which can scorch its delicate epidermis. Place it near a south or west-facing window with filtered light or in a bright, indirect light setting. Insufficient light can cause etiolation, where the plant stretches and loses its compact form.
Watering Practices
Water using a “soak and dry” method, allowing the soil to dry out completely between waterings to prevent root rot. During the active growing season (spring to fall), water moderately when the soil is dry several inches below the surface, about once a week. Reduce watering significantly in cooler months as the plant enters dormancy, watering only once every two months.
Soil and Potting
A well-draining, gritty soil mix is essential for Euphorbia piscidermis to prevent waterlogging. Create a suitable potting medium using a succulent or cactus mix amended with perlite, pumice, or coarse sand to enhance drainage. Terracotta pots are often preferred as they promote airflow and allow excess moisture to evaporate more readily.
Temperature and Humidity
This succulent prefers warm, dry environments and is sensitive to cold. It thrives in temperatures above 55°F (12°C) and requires frost protection. While it tolerates partial shade, it dislikes cold and humid conditions. Good ventilation is beneficial to prevent overly humid environments.
Fertilization
Fertilization is not a frequent requirement for Euphorbia piscidermis. During its main growing period (April to October), apply a diluted organic or balanced compound fertilizer every 20 days. Dilute the fertilizer to half-strength or less to avoid over-fertilization, and cease fertilizing entirely after October.
Propagating Euphorbia piscidermis
Propagating Euphorbia piscidermis through stem cuttings can be challenging. When taking a cutting, use a clean, sharp knife. Immediately wash the wound to remove the milky white latex sap, which can inhibit rooting. Allow the cutting to callus for a week or more in a dry, airy location until dry and sealed. Once callused, plant the cutting in a well-draining succulent soil mix, keeping the soil barely moist until roots develop.
Addressing Common Issues
Root rot typically results from overwatering or poorly draining soil. Ensure the soil dries completely between waterings and use a gritty mix to prevent this. Etiolation (stretched, weak growth) indicates insufficient light, requiring a move to a brighter location. Though generally problem-free, Euphorbia piscidermis can be affected by mealybugs. Inspect the plant regularly and treat infestations promptly with an appropriate horticultural insecticide or by dabbing pests with rubbing alcohol.
Important Safety Information
All Euphorbia species produce a milky white latex sap when damaged. This toxic latex can cause significant skin irritation. It is particularly dangerous if it contacts eyes or is ingested, potentially leading to severe reactions or permanent damage. Always wear gloves and eye protection when handling the plant, especially during repotting or propagation, to avoid sap exposure.