Acacia (Leguminosae)

The name derives from the Greek akakía «acacia». This common name is erroneously applied to Robinia (see), as well as the Acaia is called Mimosa, which, in botany, is another genus of the same family; A. farnesiana is also called gaggia. It is a genus composed of about 500 species of shrubs or small flowering trees, of which those cultivated for ornamentation are mostly Australian, while part of the African ones have a certain economic importance because they exude a resin from which the arabic gum is extracted. Of varying height and posture, they also have variety characteristics in the foliage: many species have bipinnate leaves, while most Australian species have petioles enlarged to form leaf laminae (phyllodes). The flowers are yellow, formed by globular flower heads that appear feathery because of the numerous colored stamens and can be isolated or grouped in long and pendulous racemes. The seeds are contained in pods as in all Leguminosae.

Acacia Clair de lune mistakenly called Mimosa
Acacia Clair de lune mistakenly called Mimosa

Cultivated species Acacia:

A. bayleyana (m 4,50-6), gray-green foliage, compound leaves (up to 20 pairs of leaflets), longer racemes of leaves with showy golden-yellow flowers, blooms since January in mild climate; A. decurrens variety dealbata (m 15), rustic, arborescent, pale or silver-gray leaves formed by 30-40 pairs of leaflets, long pale-yellow racemes also with 30 flowers; many varieties and hybrids have been derived, including A. hanburyana; A. howittii known as “clair de lune” due to the pale yellow of its flowers; A. longifolia floribunda variety, a shrub that bears the foliage mainly at the tip of the branches, linear phyllodes (about 6 cm), acuminates, yellow-live flowers in small spikes and blooms in spring; A. melanoxylon, of considerable development, which with its strong roots helps to curb sandy soils and is also used for its wood; Acacia poda-lyriifolia (about 4 m), shrub with ovate and pubescent fillias and simple racemes but with numerous flower heads, which blooms in winter; A. retinodes, a small tree with lanceolate phyllodes, racemes composed of more than 30 lemon-yellow flowers, which blooms all year round and, since it bears the calcareous soil, is often used as a rootstock for more delicate species; Acacia saligna bears more than the others the salty winds and the proximity of the sea; it is also present in Italy.


acid and very permeable soil, sunny position, sheltered from the wind, minimum temperatures of 7-13 °C, lower for short periods. Pruning is carried out after flowering or directly, cutting off the flowering branches, at the end of winter or spring, trying to contain the plants in the desired height and shape. They reproduce by seed in spring or multiply by semi-hard wood cuttings at the beginning of the summer in multiplication tanks; the grafts are also performed at the beginning of the summer, almost always on A. retinodes, sometimes on A. longifolia.