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23-544: The Index Herbariorum provides a global directory of herbaria (singular, herbarium ; plural, 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 index

46-402: 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 . A xylarium is a herbarium specialising in specimens of wood. The term hortorium (as in

69-497: 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. Many kinds of scientists and naturalists use herbaria to preserve voucher specimens; representative samples of plants used in

92-630: A long period of time. 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

115-465: A particular study to demonstrate precisely the source of their data, or to enable confirmation of identification at a future date. They may also be a repository of viable seeds for rare species. Many universities, museums, and botanical gardens maintain herbaria. Each is assigned an alphabetic code in the Index Herbariorum , between one and eight letters long. The largest herbaria in

138-429: 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

161-452: 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. The large herbaria have many exsiccata series included in their collections. Most herbaria utilize

184-433: Is used to make flat dried flowers for pressed flower craft . Specimens prepared in a plant press are later glued to archival -quality card stock with their labels, and are filed in a herbarium . Labels are made with archival ink (or pencil) and paper, and attached with archival-quality glue. A modern plant press consists of two strong outer boards with straps that can be tightened around them to exert pressure. Between

207-485: The hortus siccus (1566) of Petrus Cadé. 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. 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

230-515: The Liberty Hyde Bailey Hortorium ) has occasionally been applied to a herbarium specialising in preserving material of horticultural origin. 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

253-543: 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. 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

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276-450: The boards, fresh plant samples are placed, carefully labelled, between layers of paper. Further layers of absorbent paper and corrugated cardboard are usually added to help to dry the samples as quickly as possible, which prevents decay and improves colour retention. Layers of a sponge material can be used in order to prevent squashing parts of the specimens, such as fruit. Older plant presses and some modern flower presses have screws to supply

299-406: 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. During the drying process the specimens are retained within their flimsies at all times to minimize damage, and only

322-487: The herbarium and placed into pigeonholes in herbarium cabinets. 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. Herbarium collections can have great significance and value to science, and have many uses. Herbaria have long been essential for

345-439: The important holdings of each herbarium's collection. This botany article is a stub . You can help Misplaced Pages by expanding it . Herbaria 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. The specimens in

368-466: 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. 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

391-751: 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. No matter

414-436: The pressure, which often limits the thickness of the stack of samples that can be put into one press. Luca Ghini (1490—1556) Italian physician and botanist, created the first recorded herbarium, and is considered the first person to have used drying under pressure to prepare a plant collection. William Withering English botanist, geologist, chemist and physician wrote popular books on British botany , and by describing

437-688: 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. Modern scientists continue to develop novel, non-traditional uses for herbarium specimens that extend beyond what the original collectors could have anticipated. Specimens housed in herbaria may be used to catalogue or identify

460-529: 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. 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

483-401: The world, in approximate order of decreasing size, are: Plant press A plant press is a set of equipment used by botanists to flatten and dry field samples so that they can be easily stored. A professional plant press is made to the standard maximum size for biological specimens to be filed in a particular herbarium . A flower press is a similar device of no standard size that

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506-638: Was originally published by the International Association for Plant Taxonomy , which sponsored the first six editions (1952–1974); subsequently the New York Botanical Garden took over the responsibility for the index. The Index provides the supporting institution's name (often a university, botanical garden, or not-for-profit organization), its city and state, and each herbarium's acronym , along with contact information for staff members and their research specialties, and

529-583: Was then glued onto a page in a book and annotated. 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. Although Ghini's herbarium has not survived, the oldest extant herbarium is that of Gherardo Cibo from around 1532. and in the Lower Countries

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