Families of Vascular Plants - Botany 307F

Herbaria and herbarium specimens


This page answers the following questions:

ROM Vascular Plant Herbarium (TRT)

For information on herbarium specimens, and on how to makes good ones, click here or here.

Herbaria are collections of pressed, dried, and labeled plant specimens that are kept in systematic order. Herbaria vary from simple scrapbooks to vast collections of millions of specimens that are housed in botanical gardens or other botanical research institutions. Herbaria around the world are known by their acronyms, i.e. one to several letters by which the collection is known to the international botanical community. Thus, the Vascular Plant Herbarium (formerly at the University of Toronto, and now housed in the Center for Biodiversity & Conservation Biology of the Royal Ontario Museum) is known as TRT. Index Herbariorum (Holmgren et al. 1990) lists the herbaria of the world and gives information not only about names and acronyms, but also about mailing addresses, telephone numbers and e-mail addresses, staff, and important collections (click HERE for the online information about North American herbaria). Boivin (1980) provides a list of Canadian herbaria annotated with information about their history and significant collections (click HERE to visit the web site for the Fowler Herbarium at Queen's University in Kingston ON). [back to top of page]

[examing herbarium specimens]The information on the label of a herbarium specimen includes not only the name of the species, but also where the specimen was collected, when, and by whom. Click here for an annotated image of a herbarium specimen label in order to see how the information described above is presented. When correctly identified, herbarium collections thus represent information about the distribution, frequency, and abundance of species, and whether these parameters have changed over time. Herbarium specimens also represent authentic samples of species with which to document the morphological and other variation that a species exhibits.

In addition to the information on the specimen label that, typically, was provided by the collector, herbarium specimens may also include additional information as a result of their use in different kinds of studies. For example, the specimens in a herbarium may be used in taxonomic and ecological studies, as well as floristic ones. Thus, a specimen may have been studied by a specialist preparing a taxonomic revision of a particular group. In this case it is important that the specialist indicate which specimens were consulted in arriving at her or his conclusions. Similarly, a specimen examined in the course of floristic or other studies may be annotated to reflect the fact that its data have been recorded in a database or have been used to prepare a distribution map. In other cases, specimens may be annotated to reflect the fact that they represent plants from which materials (e.g. seeds, fruits, leaves, stems, or roots) have been collected, either dead or alive, as part of horticultural, pharmacological, or other investigations. At any time, anyone who examines specimen may be able to revise its identification, either to correct an earlier, mistaken identification, or so as to reflect more up-to-date nomenclature or taxonomic concepts. All of these annotations document the ways in which the specimen has been used, and thus its value to a host of different branches of science; click here or here to see examples of some of these different kinds of annotations. [back to top of page]

In the past, herbarium specimens were labeled by transcribing data directly onto the herbarium sheet itself, by hand. In the 19th century printed labels identifying the collector, institution, or study area came into use. Blank spaces were provided in which collectors could write locality information and an identification. Typewritten labels became increasingly popular during the 20th century until they were superceded by computer-generated ones. [back to top of page]

Computerization has affected not only how labels are produced, but also the way in which herbarium data are stored and used. Whereas prior to the advent of computers the herbarium itself was the database, nowadays the same data that appear on the label can also be stored, manipulated, and made use of within a computer. The label for which a link is provided above was generated from just such a computerized database using a set of word-processor macros, in accordance with the principle that data should be keyboarded only once in order to minimize errors of transcription. Elsewhere, geographic coordinates can be used to plot distribution maps as has been done with species of orchids in Muskoka district, Ontario (e.g. Corallorhiza trifida). [back to top of page]

Specimen databases have been used to document the status of plants that are rare or at risk in Ontario. Specimen databases can also be used together with taxon databases to produce floristic accounts or taxonomic treatments. This is how the Muskoka flora web pages were produced, using a combination of off-the-shelf commercial software and special-purpose programming. Elsewhere, sophisticated software packages have been developed for this purpose, such as ALICE and PANDORA. Exploitation of these tools, as well as the need to share data between workers and institutions, make it increasingly imperative to standardize the way in which specimen data are recorded; a description of one such standard can be found at HISPID3 (Herbarium Information Standards and Protocols for Interchange of Data ver. 3), and there is an organization that actively seeks to promulgate such standards, namely the Taxonomic Databases Working Group (TDWG) that met in Toronto in 1996. [back to top of page]


kewlogo-tiny.jpg (4600 bytes) The Herbarium Handbook, rev. ed. (Bridson & Forman 1992)

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Please send your comments to tim.dickinson@utoronto.ca; last updated 16-Apr-2001