Picking Pycnantha

Picking Pycnantha

Dr Bernadette Hince looks at our national floral emblem, the golden wattle

Ellis Rowan, Acacia pycnantha Benth., family Fabaceae (detail), 1880s, nla.cat-vn2841608

A hundred years ago, on an August day in 1917, horticulturist Charles Weston picked specimens of a wattle that was flowering on the slopes of Mt Jerrabomberra, close to the border between New South Wales and the recently created Federal Capital Territory. Its common name ‘golden wattle’ is a tricky one, because many wattles could be called golden when they are flowering. But this one, which is widespread in southeastern Australia, is now unmistakable through its official role as our national floral emblem—Acacia pycnantha Benth. as it is known to botanists.

As officer-in-charge of afforestation of the newly developing city of Canberra to Mt Jerrabomberra’s west, it was Weston’s responsibility to oversee landscaping. He was eager to find plants suited to the relatively harsh climate of the Australian capital, with its hot dry summers and below-freezing winters. In searching for the best trees to plant, Weston established a local nursery and experimented with breeding and planting. He also travelled widely to collect plants and seeds. His correspondents included the botanist Joseph Maiden, director of Sydney’s Royal Botanic Garden, who in 1909 had helped create Wattle Day.

It was almost certainly Weston who sent samples of the Mt Jerrabomberra wattle to Maiden, who honoured him in 1920 by giving it the name of Acacia westonii (as 'Westoni'). But Maiden himself had some doubts as to whether Acacia westonii was in fact a distinct species. Later botanists with more specimens at their disposal decided that it would be included in a broader interpretation of our variable and widespread national floral emblem, and the reference to Weston’s role disappeared from the botanical name.

The practice of naming plants is one that generates a lot of historical information. The herbarium specimens used when botanists describe a new species are labelled with the date and location of collection. Because of this, we know exactly when the explorer and surveyor Thomas Mitchell collected his specimens of golden wattle: on 5 July 1836, between the Loddon River and Pyramid Hill in Victoria, during his third expedition into inland Australia.

These specimens went to English botanist George Bentham, a remarkably productive man with a great interest in classifying plants. The Library is lucky to hold Bentham’s seven-volume Flora Australiensis: A Description of the Plants of the Australian Territory published in the 1860s and 1870s. In 1842, using Mitchell’s specimens, Bentham described the wattle and named it Acacia pycnantha. That is why there is now an abbreviation of his name, ‘Benth.’, at the end of the scientific name.

Dr Bernadette Hince is an honorary lecturer in the ANU College of Arts and Social Sciences. She was a Harold White Fellow at the Library in 2006.