Have you ever wondered which plants successfully survive in the harsh and extreme environments of savannas and deserts? If so, you will surely find it fascinating to know in depth the acacia tortilis, Also known as parasol acacia o flat-topped acaciaThis tree is icon of the African savannas and one of the most spectacular examples of adaptation in the plant kingdom, providing shade, food and shelter to countless species.
Main characteristics of Acacia tortilis
- Scientific name: acacia tortilis
- Family: Fabaceae
- Origin and distribution: Native to Africa and southwest Asia, it is especially common in savannah and semi-arid or desert areas, from South Africa to North Africa and into the Middle East.
Acacia tortilis can reach between 12 and 18 meters in height, although it is often observed lower due to the harsh conditions of its environment. Its The crown is wide, parasol-shaped and spreading, acting as a natural refuge from the intense solar radiation of the savannahs. trunk is straight or slightly curved, with a bark that usually comes off in elongated flakes, especially in adult specimens. It stands out for its deep root system, which allows it to access groundwater in times of drought.
The leaves are deciduous and bipinnate, composed of multiple leaflets of bluish-green or grayish color which help reduce water loss through evapotranspiration. On the branches, even from an early age, they stand out long white thorns, sometimes mixed with shorter, curved spines forming an effective defense against herbivores.
Flowers Acacia tortilis flowers appear in small, globose inflorescences, barely 1 cm in diameter, in yellow or cream tones. These inflorescences have a delicate aroma and appear mainly in summer, although, if the weather permits, they can also bloom in winter. fruit is an elongated and spirally twisted legume, dark brown when ripe, and contains seeds of high nutritional value.
Distribution, habitat and adaptability
La Acacia tortilis is widely distributed in warm, dry regions of Africa and southwest Asia. It can thrive on plains, embankments, depressions, semi-arid zones, and even in true deserts and mountainous areas up to 2000 meters above sea level.
- supports extreme temperatures and long periods of drought, thanks to its ability to store water in the trunk and its small leaves.
- Tolerates poor, rocky and sandy soils, provided they have good drainage.
- Extensive root system which also helps the erosion control on degraded soils.
Diversity: Subspecies and varieties
The species Acacia tortilis presents several subspecies, each adapted to specific ecological conditions in its area:
- Acacia tortilis subsp. heteracantha: Tree up to 15 meters tall, with a broad crown, pubescent branches, and glabrous pods. Distributed in southern Africa.
- Acacia tortilis subsp. Raddiana: Medium-sized, flat crown, pubescent twigs, associated with Saharan areas and the Sahel.
- Acacia tortilis subsp. spirocarpa: Tree 2 to 21 meters, very spreading crown, very hairy pods, common in East Africa.
- Crinita variety: Pods covered with long, scattered whitish hairs.
Ecological importance and traditional uses
- Provides vital shade for the fauna and flora of the savannah, protecting animals and plants from high temperatures.
- Provides food to herbivores such as giraffes, elephants, zebras, impalas, and baboons. Its seeds are rich in protein (up to 28,5% crude protein), and shoots or pods are essential fodder during difficult times.
- Serves as habitat and support for birds, insects, and other animals. Several species of birds, such as secretary birds, lizard birds, and vultures, nest in its branches.
- Fixes nitrogen in the soil thanks to symbiotic bacteria, promoting fertility even in poor soils.
- It is used in the fight against erosion and restoration projects for degraded areas.
- For local communities, it is a source of wood for construction and fuel, agricultural tool, production of gum arabic, medicinal uses (vermifuge and dermatological applications), and even in crafts.
Reproduction and propagation: A complete guide to growing Acacia tortilis
The main reproduction is by seedsGermination success depends on proper seed preparation, as their seed coat is very hard:
- Scarification: Lightly sand the outer layer or briefly immerse them in boiling water (1 second) and then transfer them to room temperature water. Alternatively, soak them in warm water for 24 to 48 hours.
- Sowing: Use a well-aerated, well-drained potting mix. Ideally, a combination of sand, pumice, and coconut fiber. Conventional potting soil is not suitable, as it retains too much moisture.
- Planting depth: Bury the seed 1 to 1,5 cm deep. Cover lightly and moisten the substrate well.
- Ambient: Keep the pot in a warm, sunny location, facing east or west. Ideal temperatures range between 24 and 30°C. It can be covered with plastic wrap to maintain humidity, but ventilate daily.
- Irrigation: Keep the substrate slightly moist, never waterlogged. It's better to err on the side of dryness than overwatering.
- Germination time: Between 1 and 4 weeks, although some seeds may take longer.
- When the seedling has several true leaves, transplant to a larger pot using the same aerated substrate.
- After hardening, it can be acclimatized to a Mediterranean garden or warm outdoor areas, always avoiding frost!
Acacia tortilis does not require frequent pruning or fertilizationIt is resistant to common pests and diseases, although in its habitat it can be affected by insects of the Bruchidae family on the pods and by lizards on young seedlings.
Garden care and cultivation
- Exhibition: Full sun, in a warm environment all year round.
- Ground: It prefers poor, sandy, rocky, but well-drained soils.
- Irrigation: Moderate watering, always allowing the substrate to dry between waterings. Extremely drought-tolerant.
- Frost: Sensitive, it only tolerates very light and short-term frosts in the adult state (maximum -2 ºC).
- Pruning: It's not necessary. Just remove dry or damaged branches.
- Subscriber: Not essential, although it may benefit from a light addition of cactus fertilizer during growth.
- Plagues and diseases: Generally very hardy. Seedlings may occasionally suffer damage from local fauna.
La acacia tortilis It is key to the biodiversity of savannas: it stabilizes soils, provides shelter and resources for animals and plants, enriches the soil with nitrogen, and is essential for the subsistence of human and livestock communities. However, it faces threats such as deforestation, overexploitation and climate changeProtecting their populations involves promoting ecological restoration, sustainable management of forest resources, and educating about their ecological and cultural importance.
The Acacia tortilis, with its majestic silhouette and ability to survive in the most extreme environments, symbolizes the resilience and value of biodiversity in the planet's savannas and deserts. Its cultivation and conservation, besides being an exciting challenge, is also an opportunity to support ecosystem regeneration and soil improvement in arid and degraded areas. If you enjoy gardening in warm climates, choose the Acacia tortilis for your garden and you'll have a resilient, elegant tree steeped in history.
Further information: Welwitschia mirabilis: the most resistant plant.