Acacia farnesiana in southern Europe

by Priya Rangan

Acacia farnesiana, a plant native to Mesoamerica and the Caribbean, had already arrived in Australia prior to British settlement of the continent. How did it get there? We thought it might have been via the Portuguese, who may have brought the plant to southern Europe and then spread it to their trading forts and settlements in Asia. Manuel decided to pursue his doctoral studies in Geography and Spatial Planning (CEGOT), at the University of Porto, and focus his thesis on the history of how A. farnesiana arrived in southern Europe. See the outline of his research presentation at the 4^th International Symposium on Weeds and Invasive Plants held in May 2014 at Montpellier, France.

Acacia Dan

By Dan Murphy

As a plant systematist I work in a herbarium as part of a botanic garden (but the views expressed here are mine alone). My research covers the areas of plant identification, taxonomy, systematics, classification and biogeography of flowering plants, using mostly molecular data but also morphology.  I have quite broad interests in plants and their uses – including horticulture, gardening and agriculture – which I will write about elsewhere.  However, most pertinent for this blog are my specialised interests in several major plant groups, distributed mostly in Australia and neighbouring regions, including Acacia and related legumes; the molecular systematics and identification of grasses; forays into the fascinating Adansonia and Proteaceae (Persoonia); and plant distributions (the science of biogeography) generally.

A big challenge in this research is answering the “when” questions.  In many regions plants are regarded as having a “natural” distribution if they were present before (a somewhat arbitrary) cut-off date.

Acacia farnesiana in Australia and Fiji

By Christian Kull

One of the key questions of our current research project is how, when, and why the ‘mimosa bush’ or ‘cassie’ tree got to Australia. Acacia farnesiana, also known as Vachellia farnesiana (if you agree with the splitting of the acacia genus) is presumed by many botanists to be native to a broad swath of the Americas, from Bolivia north to Texas. Yet it exists all around the tropical and subtropical world. The first British explorers of interior Australia found it growing all over the interior northern part of the continent. How did it get there, then? How long has it been there? The answer matters, because environmental managers these days want to know if a plant is ‘native’ or ‘alien’, as this has repercussions (for better or worse) on how they approach it.