Euphorbia poissonii - Poison Spurge

Morphological Characteristics

Euphorbia poissonii is a highly toxic, shrubby succulent known for its upright growth and sharp spines. It typically grows up to 1–2 meters (3–6 feet) tall, forming thick, columnar stems that branch sparingly. The stems are ribbed with prominent spine shields along the edges, bearing reddish to brown spines.

The skin is gray-green with a waxy surface that helps reduce water loss in its native arid habitat. During the growing season, small, yellowish-green cyathia (Euphorbia flowers) emerge at the stem tips, often accompanied by reddish bracts.

Growth Habits

This plant grows slowly and prefers dry, warm conditions. It remains upright and compact, making it suitable for large containers or dryland gardens in frost-free climates. In native regions, it’s also used as a living fence due to its defensive properties.

Maintenance Points

• Lighting: Requires full sun to partial shade. Strong light enhances growth and spine coloration.

• Watering: Drought-tolerant. Water thoroughly only when soil is fully dry. Avoid watering in cold months.

• Soil: Needs very well-draining mix—cactus soil amended with sand or perlite.

• Temperature: Thrives in 20–35°C (68–95°F). Not frost-hardy—protect from temperatures below 10°C (50°F).

• Fertilization: Light feeding with diluted succulent fertilizer during active growth (spring/summer).

• Handling: Use extreme caution. The milky latex sap is highly toxic and irritant—wear gloves and eye protection when repotting or trimming.

• Pests: Usually pest-resistant. Keep dry to avoid root rot or fungal infections.

Display & Use

Euphorbia poissonii is ideal for collectors of rare, unusual, or defensive plants. Its architectural form makes it a striking focal point in xeriscapes or desert-themed container arrangements. Best used where pets and children cannot reach, due to its highly caustic latex.