Unlocking an Historic Weed Herbarium Collection
Curation, Data improvement, Comparative studies
An herbarium is a collection of preserved plant material—dried and pressed—used for scientific research. The National Herbarium of New South Wales (NSW), located at Mount Annan, houses over 1.4 million specimens, each representing a moment in time, a place, a purpose, and holding valuable information that can be used to understand our flora in a fast-changing environment. In 2023, NSW received a significant donation: the entire herbarium collection of the Tamworth Agricultural Institute (TARCH), comprising approximately 8500 specimens with a geospatial focus on a 200 km radius around Tamworth. It includes key reference sets for documenting new weed naturalisations over the past two decades, Senecio madagascariensis plant-insect specificity studies, southeastern Australian Rubus, and Rytidosperma from pasture domestication research. A particularly challenging subset of 673 specimens, collected in 1972-74 from natural pastures in the Northwestern Slopes of NSW, required extensive curation including physical restoration, data enhancement, and taxonomic updates. Data enhancement involved decoding 213 cryptic locations from pre-1966 grid references in yards, converting them into latitude and longitude using historical maps and Excel formulae, and verifying with QGIS. Now housed in a state-of-the-art facility, these specimens are accessible with improved data and will soon be available on the Atlas of Living Australia (ALA) and the Australian Virtual Herbarium (AVH). This collection expands reference material for weeds in NSW for researchers, land managers, and the public. We are pursuing funding to carry out comparative studies using this invaluable scientific collection to examine changes in weed distribution and appearance patterns over time. We appreciate the support of the NSW Weed Society and Botanic Gardens of Sydney for funding the curatorial restoration of this important resource.