Know your alien invasive plant: Black Wattle
Hillcrest Conservancy will produce weekly articles regarding the various alien invasive plant species in the Highway area to help the community identify and eliminate them.
PHOTO: www.wikimedia.org
THIS week, Hillcrest Conservancy takes a look at the Black wattle as part of its series of articles on alien invasive plants to help the community to identify and eradicate them from their gardens.
The scientific name for the Black Wattle is Acacia mearnsii (Fabaceae) and in Afrikaans it is known as the Swartwattel.
We have to date not discussed many of the trees or plants that fall into Category 2. These are trees that normally have a commercial value and would be farmed for this purpose. They are often invasive and a permit would be required to grow these as a commercial crop. The permit conditions are strict and it is the farmer’s responsibility to ensure that any plants escaping from his property have to be controlled. When these plants escape or are found on private land and are not being farmed they will need to be removed.
What is its invasive status in South Africa?
The Black Wattle is just one of many of these plants in Category 2 and we will cover these in the next few articles.
Description:
An evergreen tree growing to heights of between five and 10 metres. The leaves are a dark olive green and have fine hairs on them. The flowers which appear in August and September are clusters of small round balls varying in colour from white to yellow.
Where does this
species come from?
This plant was originally introduced from Australia and Tasmania and the bark was used in the tanning of hides. Due to its fast growth, it is also used extensively for fire wood and charcoal.
Where is it a problem?
Throughout the Western and Eastern Cape, KZN, Mpumalanga and Gauteng.
Why is it a problem?
The wattle spreads quickly and invades grassland and stream banks where it clogs rivers and causes soil erosion. Very little will grow in a dense thicket of this species.
How does it spread?
The seeds are carried downstream. Each tree produces thousands of seeds annually. This species is very difficult to control as seeds can lie dormant for many years.
