What is a herbarium?

A herbarium (Latin: hortus siccus) is a collection of plant samples preserved for long-term study, usually in the form of dried and pressed plants mounted on paper. The dried and mounted plant samples are generally referred to as herbarium specimens. Other materials in the herbarium may include loose seeds, dried bulky fruits, algae, fungi, wood sections, pollen, microscope slides, silica-stored materials, DNA extractions, and fluid-preserved flowers or fruit. Herbaria (plural for herbarium) also store and manage data sets, botanical illustrations, photographic slides, images, maps, and often have libraries of relevant literature needed for consultation by researchers working with the specimens.

Herbaria are usually affiliated with universities, museums, or botanical gardens, but some may be private which was more common historically. The oldest extant herbaria date from around the 1540s, mostly associated with Luca Ghini and his botanical teachings in northern Italy. There are now around 3,500 registered herbaria in 183 countries totaling nearly 400 million specimens. Herbaria are registered through the Index Herbariorum, and each is assigned a unique official acronym (herbarium code) that is used as a standard for referring to the institution and its specimens.

Approximate list of the twelve largest herbaria in the world (also see List of Herbaria at Wikipedia and Index Herbariorum, the official registry):

ACRONYM LOCATION NAME SPECIMENS (CA. MILLIONS)
K London, U.K. Royal Botanic Gardens, Kew 8.1
P, PC Paris, France Museum National d’Histoire Naturelle 8
NY New York, USA New York Botanical Garden 7.9
MO St. Louis, MO Missouri Botanical Garden 6.9
LE St. Petersburg, Russia Komarov Botanical Institute 6
G Geneva, Switzerland Conservatoire et Jardin botaniques de la Ville de Geneve 6
W Vienna, Austria Naturhistorisches Museum Wien 5.5
BM London, U.K. British Museum of Natural History 5.2
US Washington, D.C. Smithsonian Institution 5.1
L, U, WAG The Netherlands The Nationaal Herbarium Nederland (NHN) 5
GH, A, AMES, ECON, FH Cambridge, Massachusetts Harvard University Herbaria 5
FI Florence, Italy Natural History Museum 5

The University of Florida Herbarium (FLAS) is the oldest (est. 1891), largest, and most comprehensive botanical collection in Florida with almost 500,000 specimens. Our acronym, “FLAS“, is derived from our affiliation with the Florida Agricultural Experiment Station. It is the 4th largest herbarium in the southeastern United States (the acronyms of the larger herbaria in the southeast being DUKE, NCU, and TENN). The FLAS collection includes specimens from every continent (including bryophytes from Antarctica), but the geographic focus of the collection is the southern USA, Caribbean basin, and Neotropics. The herbarium’s collections are actively growing; approximately 2500 plant specimens and 300 library items are added each year.

Approximate holdings:

320,000 vascular plants
70,000 bryophytes
16,000 lichens
3,500 algae
55,000 fungi
16,000 wood samples
3,200 seed vials
16,000 library books, journals, reprints, maps, and illustrations

Like all museum collections, herbarium specimens are stored in perpetuity. The successful long-term storage of specimens necessitates specialized materials, procedures, and facilities. Paper products, inks, and adhesives all strive to be archival, meaning they are durable and lack constituents (e.g. acids) that may cause the specimens to significantly degrade over time. To further minimize degradation, specimens are stored in tightly sealed cabinets (preferably metal). Maintaining a cool, dry storage environment helps reduce the risk of insect and fungal damage to specimens. All incoming plant materials, including both field collections and loans of mounted specimens, are frozen at 0° to -30°C for 14 days to neutralize pests. When an insect infestation occurs, specimens may need to be treated with insecticidal fumigants. Prolonged exposure to light, overcrowded storage, and mishandling by humans may  cause irreversible specimen damage.

How are herbarium specimens used?

Herbarium specimens are useful as references for plant identification and for the determination of plant locations and ranges, abundance, habitat, and flowering and fruiting periods. They are used for studies in which the differences between plant species are evaluated and described (monographs) or in which the species growing in a region are reported (floras). The herbarium is also the cornerstone of nomenclature and taxonomy, by securing a
scientific name to a plant specimen (type specimen) thus stabilizing the identity and communication of a particular species.

Plant systematics is the core research emphasis for herbarium staff. There are four main areas in systematics —

The results of systematic research help us to better understand plant identities and relationships.

Herbarium specimens are also useful in many other disciplines. Examples of other uses include:

The library is an essential resource when working with plant specimens in the collection. The literature in the FLAS library contains descriptions, geographical ranges, and keys for differentiating species of vascular plants; floristic treatments of various countries and regions throughout the world; and information regarding botanical morphology, plant names (nomenclature), plant collectors, and economic botany.

Just as the materials in a library are arranged in a specific order (usually the Library of Congress or Dewey Decimal catalog systems), the plant materials in most herbaria are organized in a very precise manner. In the FLAS Herbarium, the organizational scheme for the plant collections is taxonomic, geographic, and alphabetic. Each specimen has an exact location where it is stored. This insures that specimens can be easily located for study. As new research results in substantiated published changes in nomenclature and systematic relationships, the herbarium collections are usually annotated, relabeled, and/or reorganized accordingly.

FLAS collection activities

Personnel in the FLAS Herbarium include 3 faculty and full-time staff, 8 research associates, 1 postdoc, 5 graduate students, 1–2 undergraduate researchers, 15–20 part-time and student employees, and 10–20 volunteers.

Activities in the FLAS Herbarium can be divided into four broad areas, which parallel the overall function of the Florida Museum of Natural History.

Collections Acquisition and Care

researcher looking through microscope studying a plantCollections-Based Research

Education

Public Service

Where to go for more information

Publications

Web Pages