Opuntia dillenii, or the long-spined cactus, is a fascinating plant found in the Au Bois Vert botanical garden. Native to Mexico, this cactus belongs to the Cactaceae family. Its spines, which can reach up to six centimetres in length, make it particularly distinctive. The cladodes, or flattened segments, ensure photosynthesis and give the plant its unique appearance. Its bright yellow flowers, sometimes tinged with orange or red, measure around seven to eight centimetres in diameter. Additionally, its edible fruits, which are pink or red, range from four to seven centimetres in length.
This tree-like cactus grows to a height of one to two metres, with a similar width. It thrives in sandy, nutrient-poor, and acidic soils, with a pH of around 5. Opuntia dillenii also prefers hot and dry climates, requiring only 150 to 250 millimetres of annual rainfall. However, it can adapt to more humid conditions as long as the average annual temperatures remain between 10°C and 20°C. This plant cannot tolerate freezing temperatures, which limits its geographical distribution.
The Opuntia dillenii, or long-spined cactus, is widespread in Mexico, Florida, northern South America, and many islands of the Caribbean. It is also found in Mediterranean regions, the Canary Islands, West and East Africa, as well as on Indian Ocean islands, including Madagascar and Mauritius. This remarkable adaptability to diverse environments makes it a standout feature of the Au Bois Vert botanical garden, located near the Au Bois Vert hotel and restaurant in Ivato, Antananarivo.
Plant use
Opuntia dillenii, or the long-spined cactus, offers several interesting uses. Traditionally, its edible fruits are consumed fresh or transformed into jams and jellies. Their sweet and slightly tangy flavour makes them a valued ingredient in various culinary preparations. In addition to their pleasant taste, Opuntia dillenii fruits are rich in vitamins and minerals, providing significant nutritional benefits. The cladodes of Opuntia dillenii also possess medicinal properties. They are applied as a poultice to treat inflammations and skin wounds. Furthermore, extracts from this plant are being studied for their potential antioxidant and anti-inflammatory effects, paving the way for future therapeutic applications. At the Au Bois Vert botanical garden, Opuntia dillenii plays an important aesthetic role. Its unique silhouette and vibrant flowers add an exotic touch to the landscape. Additionally, this plant is an excellent choice for dry gardens and low-maintenance landscaping. Its ability to thrive in challenging conditions makes it a sustainable option for green spaces. Visitors to the Au Bois Vert hotel and restaurant can thus enjoy the beauty of this plant while savouring a meal or relaxing in the lodge's peaceful setting.
Key information
| Common name | Long-spined cactus |
| Scientific name | Opuntia dillenii |
| Origin | Central America and the Caribbean |
| Natural habitat | Arid and semi-arid zones, often in well-drained soils |
| Life cycle | Succulent perennial |
| Flowering period | Summer (often from June to August) |
