The Acacia Plant

The Leaf | The Inflorescence | Pollination | Seeds | Growth

Growth

Most acacias appear to produce and develop new shoots after flowering has finished. This is usually in the spring and the new growth continues throughout the summer if sufficient moisture is available. It is also at this time that the next seasons flower buds are initiated and begin to grow. This development of the buds continues during the winter until anthesis (flowering) occurs again in late winter or early spring.

In studies²³ of A. pycnantha and A. aneura it was found that floral buds were produced throughout the year, but flowering occurred only once each year in late winter in the former, and from June to October few buds were produced and most of these were later aborted as the legumes developed. However, in A. aneura flowering may occur several times during the year. This has also been observed in A. subulata and in the members of the A. uncinata group¹⁰. It has also been observed that some acacias, for example A. crassa and A. viscidula, shed some of the old phyllodes during the summer months as new growth develops, and flower buds may also develop in the axils of some of the abscissed phyllodes. It appears that chlorophyll and perhaps other nutrients such as phorphorous and nitrogen²² are withdrawn from the phyllodes, slowly turning them yellow for sometime before they fall as a mechanism for conserving the nutrients for the new growth.

The Leaf | The Inflorescence | Pollination | Seeds | Growth