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What is an Herbarium?
An herbarium is a collection of pressed, dried plants. The first herbaria (plural of "herbarium") were personal collections, that is, not institutional. Some of these early collections are known from the Italian Renaissance, and represented an increased interest in plants that began to flourish after the Middle Ages. Modern herbaria usually have their specimens of plants attached directly to large sheets of paper, most often measuring about 11.5" by 16.5". Each specimen has an informative label attached to it as well, indicating the name of the plant (if known), where it was collected, the date it was collected, and by whom. The most useful labels also include information on various features of the plant that may not be discernable in the field. Information such as flower color, fragrance, number of individual plants, their height, insect visitors, and so on are frequently used many years after the plant was collected.
After the specimens are prepared, they are housed in cases for safety. The cases may be made of metal or wood, and must keep the specimens dry and safe from insect pests. Many herbaria now have mechanized compacter systems for storage; these allow maximum storage space with a minimum of aisle space between cases. The largest herbaria in the world may contain several million specimens. In the United States, these include the New York Botanical Garden and the Missouri Botanical Garden (St. Louis), whose holdings are world-wide in scope. Academic institutions generally have smaller collections, usually featuring collections focused in a given geographic region.
Herbarium specimens frequently bear one or more annotation labels. These are labels applied to the specimen by an authority on that particular plant group, and will either verify or correct an earlier determination. The presence of an annotation label also serves as a sort of "paper trail" botanically, and indicates that the specimen itself was examined at a certain time by a certain researcher. Herbarium specimens that have been examined by authorities (and which bear their annotations) are thus more valuable. Herbaria are especially useful in taxonomic studies. Plant taxonomy is the arrangement, or classification, of similar plants into groups, or taxa, which share certain characteristics. Taxonomy also involves the correct naming, or nomenclature, of taxa. Sometimes different plant groups may seem to overlap, making it difficult to know which name to use. Herbaria are useful because their holdings represent the work of many individual collectors working at many different times and locations. When the specimens are viewed together, botanists are able to see patterns in a plant's distribution and morphology that would not have been apparent to any single collector. Plants can be grouped or separated, and names assigned, according to the patterns that may emerge. Herbaria, especially those with a regional focus, can also facilitate ecological restoration by providing records of rare plants' historical ranges. | |||
