Herbarium, a library of plants

Some libraries do not consist of books, but plants. Yes, you read correctly, real plants. These plants are, however, not alive as in a botanical garden; they are dead and mounted on boards. A herbarium has cupboards with many sheets of dried and mounted plants (a sheet with a mounted plant is called a specimen). There are approximately 3,000 herbaria around the world and they are usually associated with botanical gardens, museums, or universities. The Museum National d’Histoire Naturelle in Paris, France is the largest herbarium in the world with around eight million specimens, followed by the famous Royal Botanical Garden in Kew, London, with six million. The largest herbarium in Africa – with over a million specimens – is the National Herbarium at the South African National Biodiversity Institute in Pretoria. Even Potchefstroom boasts with a herbarium, namely the A.P. Goossens Herbarium in the botany department of the North-West University. Luca Ghini created the first herbarium in the sixteenth century. He was a professor of medicine and botany at the University of Pisa. His collection consisted of several specimens glued to decorated sheets and bound together as a book, however. It was only later that the famous Carolus Linnaeus started mounting a single specimen on a sheet and storing them separately. A specimen is a record of a specific plant that grew at a particular location at a given time. A collection in a herbarium is, therefore, a historical record of the plant diversity of a region. Different herbaria focus on different areas. Large herbaria like the Museum National d’Histoire Naturelle and Kew, contain plants from around the world. The National Herbarium in Pretoria concentrates mainly on plants from Southern Africa and the A.P. Goossens Herbarium looks at plants from the North West. Herbarium specimens are used when compiling checklists of the plants that grow in a specific region and also when writing books on plants in a particular region. When samples are collected regularly, the change of the plant diversity in that area can also be traced. Herbarium specimens are sometimes the only proof that a certain plant ever existed. Plants like these could be extinct in the wild because their habitat has been destroyed by human activity. The collections could also result in expeditions to rediscover these plants. Many new species are discovered in the cupboards of herbaria when research is done on these specimens. Herbaria provide an identification service to the public. They are well equipped with specimens with which to make comparisons and name plants. Herbarium staff often offer training and education on various topics. Researchers can generate information that managers, conservationists and the government could use to make important decisions on the environment. Herbaria do not only consist of mounted specimens, however. Other collections in a herbarium could include bark and wood, seeds, liquid-preserved exhibits (i.e. plant parts stored in a fixative), photos, illustrations and even fossils. Now you know about a different kind of library that is full of interesting and, sometimes, undiscovered information. For more information on herbaria contact Dr Madeleen Struwig (Madeleen.Struwig@nwu.ac.za).