A well-known tree because of the family it belongs to (fabaceae) is the 3-thorn acacia or, as it is known scientifically, Gleditsia triacanthos. In Europe and the rest of the world there are several species of acacias considered invasive species (currently this species is not collected in Spain).
extraordinary sound ability to multiply and the genetic evolution of this fabaceae which allows it to fight against other plants and even animals (due to the emission of repellent chemical components) means that its expansion throughout the world has been dizzying.
Gleditsia triacanthos it’s a fast growing tree and dioecious (male individuals and female individuals) that can reach 20-30 m in height in a very short time compared to other trees, about 40 years. It has a great capacity of regrowth by the roots and is resistant to pruning and drought. You could say it’s a tree of the future, almost a tardigrade of the plant world.
We dedicate this article exclusively to one of the almost 1000 species of acacias that exist all over the world, the 3-thorn acacia (Gleditsia triacanthos).
Main features of Gleditsia triacanthos or 3-thorn acacia
The 3-thorn acacia is a tree that easily exceeds 15 and 20 meters in height, with many thorns spread over its trunk and branches. Interestingly, it is a legume that does not have a nitrogen fixation system by bacterial nodules, characteristic of most species of this family.
We are going to learn about the main parts of the tree and how it differs from other acacias.
blade type: pinnate type (leaves composed of 8-20 pairs of leaflets), large (group of leaves up to 40 cm), stipulated, with a petiole 3-5 cm long. The blade is elliptical in shape.
Trunk: and branches: the trunk and the branches have thorns of considerable size, their defense system. the wood of Gleditsia triacanthos is very hardy and provides a moisture barrier, so it can be used in direct contact with water. Due to its resistance, it is used for the manufacture of beams and posts, since it is a very vertical trunk (90º angle).
Flowering: it has inflorescences up to 10 cm, green-yellow, the males without a pistil and the females with a 2-3 mm pedicel. Flowering occurs in spring (northern hemisphere) and in November and December (southern hemisphere).
Seeds: fruit of brown color and oval shape, 9-11 mm (length) x 5 mm (width). Pollination is entomophilous and seed dispersal is endozoochrous. its seeds are widely eaten by them, as they are sweet and plentiful.
Development: The 3-thorn acacia reaches childbearing age at 7 years old and lives to about 80 years.
Common names: three-thorn acacia, three-tooth acacia, donkey carob, wild carob, 3-pointed acacia, black acacia.
Currently, Gleditsia triacanthos (3-thorn acacia) is not considered an invasive alien plant in Spain, although several acacias can be found that are included in this list (see list).
types of acacia trees
The Fabaceae are a very generous family, and within the genus Acacias. About 970 species are collected in the genus Acacia stricto sensu, being the majority in the Australian country. The carob tree is a species that very well represents the Fabaceae in Spain.
Location and habitat
Gleditsia triacanthos is relatively easy to find almost all parts of the worldpreferably tropical and subtropical zones, with a certain relative humidity of the environment.
Within the genus Acacia, the greatest number are found on the African continent and, preferably, on the Oceanian continent (especially in Australia), where they grow in arid areas.
Curiosities of the acacias
One of the curiosities of the acacias, and a mechanism that facilitates the conquest of large spaces to form forests, is their defense system.
It’s virtually unique in the world of vegetables, and it’s that acacia trees, including Gleditsia triacanthos emits chemical products to the environment that are captured by other plants as a “voice of alarm” against the attack of predators. The people who pick up the transmitted signal (if they can do so) irritating or toxic components for herbivores, which can affect large mammals.
3 Thorny Acacia Growing Guide
Each time we plant a species of acacia, we must check if it is classified as invasive in our country, since it is subject to fines for omission from current legislation.
At the ornamental level, the acacia with 3 thorns does not have many qualities to plant in the garden (in fact, it is even dangerous because of the thorns on its trunk and branches), although it is always worth knowing what the main characteristics of its ecology are and how it adapts to each type environment.
read more: mimosa (Acacia dealbata) characteristics and care guide.
location of Gleditsia triacanthos
It grows in full sun, both in conditions of high environmental humidity (tropical and subtropical zones) and in desert areas (such as Australia). It is a very hardy and fast growing tree.
It tolerates all kinds of temperatures stoically, although it is a tree to be grown in hot regions.
the type of soil
Acacia de 3 espinas can be grown in all types of soils and textures, regardless of pH, organic matter or drainage. In general, it develops best in sandy and well-drained soils, with an ease in developing its roots (not stony).
Water and nutritional needs
It is a tree recognized for its excellent resistance to drought, so it can survive with very low water profiles.