A herbarium (plural: herbaria) is a collection of preserved plant specimens and associated data used for scientific study. [2]
The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sheet of paper (called exsiccatum , plur. exsiccata) but, depending upon the material, may also be stored in boxes or kept in alcohol or other preservative. [3] The specimens in a herbarium are often used as reference material in describing plant taxa; some specimens may be types, some may be specimens distributed in series called exsiccatae.
The same term is often used in mycology to describe an equivalent collection of preserved fungi, otherwise known as a fungarium. [4] A xylarium is a herbarium specialising in specimens of wood. [5] The term hortorium (as in the Liberty Hyde Bailey Hortorium) has occasionally been applied to a herbarium specialising in preserving material of horticultural origin. [6]
The techniques for making herbaria have changed little over at least six centuries. They have been an important step in the transformation of the study of plants from a branch of medicine to an independent discipline, and to make available plant material from far away places and over a long period of time. [7]
The oldest traditions of making herbarium collections have been traced to Italy. The Bologna physician and botanist, Luca Ghini (1490–1556) reintroduced the study of actual plants as opposed to relying on classical texts, such as Dioscorides, which lacked sufficient accuracy for identification. At first, he needed to make available plant material, even in winter, hence his Hortus hiemalis (winter garden) or Hortus siccus (dry garden). He and his students placed freshly gathered plants between two sheets of paper and applied pressure to flatten them and absorb moisture. The dried specimen was then glued onto a page in a book and annotated. [8] This practice was supplemented by the parallel development of the Hortus simplicium or Orto botanico (botanical garden) to supply material, which he established at the University of Pisa in 1544. [9]
Although Ghini's herbarium has not survived, [10] the oldest extant herbarium is that of Gherardo Cibo from around 1532. [11] and in the Lower Countries the hortus siccus (1566) of Petrus Cadé. [12] While most of the early herbaria were prepared with sheets bound into books, Carl Linnaeus came up with the idea of maintaining them on free sheets that allowed their easy re-ordering within cabinets. [13]
Commensurate with the need to identify the specimen, it is essential to include in a herbarium sheet as much of the plant as possible (e.g., roots, flowers, stems, leaves, seed, and fruit), or at least representative parts of them in the case of large specimens. To preserve their form and colour, plants collected in the field are carefully arranged and spread flat between thin sheets, known as flimsies (equivalent to sheets of newsprint), and dried, usually in a plant press, between blotters or absorbent paper. [14]
During the drying process the specimens are retained within their flimsies at all times to minimize damage, and only the thicker, absorbent drying sheets are replaced. For some plants it may prove helpful to allow the fresh specimen to wilt slightly before being arranged for the press. An opportunity to check, rearrange and further lay out the specimen to best reveal the required features of the plant occurs when the damp absorbent sheets are changed during the drying/pressing process.[ citation needed ]
The specimens, which are then mounted on sheets of stiff white paper, are labelled with all essential data, such as date and place found, description of the plant, altitude, and special habitat conditions. The sheet is then placed in a protective case. As a precaution against insect attack, the pressed plant is frozen or poisoned, and the case disinfected.
Certain groups of plants and fungi are soft, bulky, or otherwise not amenable to drying and mounting on sheets. For these plants, other methods of preparation and storage may be used. For example, conifer cones and palm fronds may be stored in labelled boxes. Representative flowers or fruits may be pickled in formaldehyde to preserve their three-dimensional structure. Small specimens, such as saprophytic and plant parasitic microfungi, mosses and lichens, are often air-dried and packaged in small paper envelopes. [3]
No matter the method of preservation, detailed information on where and when the plant and fungus was collected, habitat, color (since it may fade over time), and the name of the collector is usually included.[ citation needed ]
The value of a herbarium is much enhanced by the possession of types, that is, the original specimens on which the study of a species was founded. Thus the herbarium at the British Museum, which is especially rich in the earlier collections made in the eighteenth and early nineteenth centuries, contains the types of many species founded by the earlier workers in botany. It is also rich in types of Australian plants from the collections of Sir Joseph Banks and Robert Brown, and contains in addition many valuable modern collections. [15] The large herbaria have many exsiccata series included in their collections. [16]
Most herbaria utilize a standard system of organizing their specimens into herbarium cases. Specimen sheets are stacked in groups by the species to which they belong and placed into a large lightweight folder that is labelled on the bottom edge. Groups of species folders are then placed together into larger, heavier folders by genus. The genus folders are then sorted by taxonomic family according to the standard system selected for use by the herbarium and placed into pigeonholes in herbarium cabinets. [17]
Locating a specimen filed in the herbarium requires knowing the nomenclature and classification used by the herbarium. It also requires familiarity with possible name changes that have occurred since the specimen was collected, since the specimen may be filed under an older name.[ citation needed ]
Herbarium collections can have great significance and value to science, and have many uses. [18] [19] Herbaria have long been essential for the study of plant taxonomy, the study of geographic distributions, and the stabilizing of nomenclature. Most of Carl Linnaeus's collections are housed at the Linnaean Herbarium, which contains over 4,000 types and now belongs to the Linnean Society in England. [20] Modern scientists continue to develop novel, non-traditional uses for herbarium specimens that extend beyond what the original collectors could have anticipated. [21]
Specimens housed in herbaria may be used to catalogue or identify the flora of an area. A large collection from a single area is used in writing a field guide or manual to aid in the identification of plants that grow there. With more specimens available, the author or the guide will better understand the variability of form in the plants and the natural distribution over which the plants grow.[ citation needed ]
Herbaria also preserve a historical record of change in vegetation over time. In some cases, plants become extinct in one area or may become extinct altogether. In such cases, specimens preserved in a herbarium can represent the only record of the plant's original distribution. Environmental scientists make use of such data to track changes in climate and human impact.
Herbaria have also proven very useful as source of plant DNA for use in taxonomy and molecular systematics. Even ancient fungaria represent a source for DNA-barcoding of ancient samples. [22]
Many kinds of scientists and naturalists use herbaria to preserve voucher specimens; representative samples of plants used in a particular study to demonstrate precisely the source of their data, or to enable confirmation of identification at a future date. [14]
They may also be a repository of viable seeds for rare species. [23]
Many universities, museums, and botanical gardens maintain herbaria. Each is assigned an alphabetic code in the Index Herbariorum, between one and eight letters long. [24]
The largest herbaria in the world, in approximate order of decreasing size, are:
William Curtis was an English botanist and entomologist, who was born at Alton, Hampshire, site of the Curtis Museum.
The Australian National Botanic Gardens (ANBG) is a heritage-listed botanical garden located in Acton, Canberra, in the Australian Capital Territory, Australia. Established in 1949, the Gardens is administered by the Australian Government's Department of Agriculture, Water and the Environment. The botanic gardens was added to the Commonwealth Heritage List on 22 June 2004.
In botany, a virtual herbarium is a herbarium in a digitized form. That is, it concerns a collection of digital images of preserved plants or plant parts. Virtual herbaria often are established to improve availability of specimens to a wider audience. However, there are digital herbaria that are not suitable for internet access because of the high resolution of scans and resulting large file sizes. Additional information about each specimen, such as the location, the collector, and the botanical name are attached to every specimen. Frequently, further details such as related species and growth requirements are mentioned.
Plant collecting is the acquisition of plant specimens for the purposes of research, cultivation, or as a hobby. Plant specimens may be kept alive, but are more commonly dried and pressed to preserve the quality of the specimen. Plant collecting is an ancient practice with records of a Chinese botanist collecting roses over 5000 years ago.
The Blatter Herbarium (BLAT), in St. Xavier's College, Mumbai, is a major Herbarium in India. It is listed in the Index Herbariorum, published by the International Association for Plant Taxonomy and New York Botanical Garden. The Herbarium specializes in the vascular plants of western India; algae, mosses, and fungi of Mumbai; seed samples of medicinally and economically important plants of Maharashtra, and wood samples of Maharashtra. The institute holds the largest botanical collection in western India.
William Ramsay McNab was a Scottish physician and botanist.
The National Herbarium of Victoria is one of Australia's earliest herbaria and the oldest scientific institution in Victoria. Its 1.5 million specimens of preserved plants, fungi and algae—collectively known as the State Botanical Collection of Victoria—comprise the largest herbarium collection in Australia and Oceania.
James (Jacobus) J. Dickson (1738–1822) was a Scottish nurseryman, plant collector, botanist and mycologist. Between 1785 and 1801 he published his Fasciculus plantarum cryptogamicarum Britanniae, a four-volume work in which he published over 400 species of algae and fungi that occur in the British Isles He is also the editor of the exsiccata work Hortus siccus Britannicus, being a collection of dried British plants, named on the authority of the Linnean herbarium and other original collections (1793–1802).
The United States National Herbarium is a collection of five million preserved plant specimens housed in the Department of Botany at the National Museum of Natural History, which is part of the Smithsonian Institution. It represents about 8% of the plant collection resources of the United States and is one of the ten largest herbaria in the world.
The Index Herbariorum provides a global directory of herbaria and their associated staff. This searchable online index allows scientists rapid access to data related to 3,400 locations where a total of 350 million botanical specimens are permanently housed. The Index Herbariorum has its own staff and website. Over time, six editions of the Index were published from 1952 to 1974. The Index became available on-line in 1997.
The Kew Herbarium is one of the world's largest and most historically significant herbaria, housed at the Royal Botanic Gardens, Kew in London, England. Established in the 1850s on the ground floor of Hunter House, it has grown to maintain approximately seven million preserved plant specimens, including 330,000 type specimens. The herbarium's collections, which include specimens dating back to 1700, represent about 95% of known vascular plant genera and 60% of described fungi, with specimens collected over 260 years of botanical exploration. The herbarium processes around 5,000 specimen loans annually and hosts approximately 3,000 visitor-days of research visits each year, supporting a wide range of botanical research.
The National Herbarium of New South Wales was established in 1853. The Herbarium has a collection of more than 1.4 million plant specimens, making it the second largest collection of pressed, dried plant specimens in Australia, including scientific and historically significant collections and samples of Australian flora gathered by Joseph Banks and Daniel Solander during the voyage of HMS Endeavour in 1770.
The conservation and restoration of herbaria includes the preventive care, repair, and restoration of herbarium specimens. Collections of dried plant specimens are collected from their native habitats, identified by experts, pressed, and mounted onto archival paper. Care is taken to make sure major morphological characteristics are visible. Herbaria documentation provides a record of botanical diversity.
Fielding-Druce Herbarium, part of the Department of Biology, University of Oxford, located on South Parks Road, in Oxford, England. A herbarium is a collection of herbarium sheets, with a dried pressed specimen of the botanic species, whether they were bound into a book by one dedicated individual, or have been amassed into huge collections. They are like plant ID cards. As paper was expensive, multiple specimens are normally mounted on one sheet. The 2 cores of the Herbarium collection, are bequeathed to the University from Henry Fielding (1805-1851) containing a non-British and Irish collection. It also covers most taxonomic groups and geographical areas. It is particularly rich in nineteenth century material from the Americas and south and south east Asia. The other core a British and Irish collection from George Claridge Druce (1850-1932) in 1932, this is particularly rich in specimens from Oxfordshire, Buckinghamshire and Berkshire. Other collections were added later.
The Australasian Virtual Herbarium (AVH) is an online resource that allows access to plant specimen data held by various Australian and New Zealand herbaria. It is part of the Atlas of Living Australia (ALA), and was formed by the amalgamation of Australia's Virtual Herbarium and NZ Virtual Herbarium. As of 12 August 2014, more than five million specimens of the 8 million and upwards specimens available from participating institutions have been databased.
Patricia May Holmgren is an American botanist. Holmgren's main botanical interests are the flora of the U.S. intermountain west and the genera Tiarella and Thlaspi. Holmgren was the director of the herbarium at the New York Botanical Garden from 1981–2000, and editor of Index Herbariorum from 1974–2008.
The State Botanical Collection of Victoria, usually referred to simply as the "State Botanical Collection", at the National Herbarium of Victoria at the Royal Botanic Gardens Victoria is the single largest herbarium collection in Australia and wider Oceania.
The Linnaean Herbarium is a historically significant collection of over 13,000 dried plant and lichen specimens assembled by the Swedish taxonomist Carl Linnaeus (1707–1778). Housed at the Linnean Society of London since 1828, it forms the foundation of modern botanical nomenclature and serves as the primary reference for Linnaeus's 1753 work Species Plantarum, the starting point for modern plant taxonomy. The herbarium includes specimens from Linnaeus's botanical explorations and global collaborations, spanning early Swedish collections to acquisitions from the Americas, Asia, and Africa.