The National Herbarium of New South Wales consist of almost one million plant specimens. The majority are from within Australia and it is the largest collection in the world of the plants of New South Wales. The Herbarium's collections are built up through field collecting by staff, donations and by exchange of specimens with other herbaria in Australia and overseas.

http://www.rbgsyd.nsw.gov.au/html/science/Systematics/Herbarium.html