Overview
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Mimosa grows into a bush that may be a few
metres tall
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Mimosa pigra, also known as giant sensitive
plant, is a native of tropical America, but it is not clear how it
came to be introduced into Australia. For nearly 100 years, this
species was isolated to small communities in and around Darwin.
During the 1970s, it suddenly spread to many of the river systems
of the Northern Territory. It now covers more than 50,000 hectares
and poses a serious threat to Kakadu National Park.
Another introduced species, the Asian water buffalo, made this
spread possible. It was introduced into Australia to provide meat
and hides. Huge herds of wild water buffalo ate and trampled
virtually all palatable vegetation on the floodplains of the
Adelaide River, so that the abnormal floods of the mid-1970s
deposited vast quantities of giant sensitive plant seed onto a
ready made seedbed which was almost devoid of competing
vegetation.
Mimosa pigra is now well established in the rangelands of
the Northern Territory and continues to spread further every wet
season. The spread of mimosa is enhanced by the lack of natural
predators and its ability to produce an enormous number of
seeds.
Mimosa pigra grows rapidly, can withstand drought and its
seed can float. The seed is mainly spread by floodwaters, so it can
establish dense prickly thickets along watercourses and on
floodplains. These impenetrable thickets inhibit access to
waterways, smother pastures and alter the natural ecology in
conservation areas.
To see a recent list of research on Mimosa pigra
click here .
