From Plant Press, Vol. 23, No. 2, April 2020.
By John Boggan
If you have looked for a type specimen recently in the United States National Herbarium (US), you may have noticed that things have changed…a lot. An ongoing rearrangement of the Type Herbarium has addressed two issues: overcrowding of the collection due to growth, and a phylogenetic arrangement that has become increasingly outdated.
A botanical type specimen is a physical specimen, usually a pressed herbarium sheet, designated by the author of a new taxon to serve as a permanent reference point for the published name. Type specimens are critical to research as they provide an unambiguous representative of the taxon, provide physical details that a written description may not, and allow subsequent researchers to study and understand how the name should be applied.
In my position as the Type Registrar, I assist the management and curation of the digital records in our Type Register and the physical specimens in our Type Herbarium, one of the largest and most important collections of type specimens in the world. Our type collection is well-documented, with each specimen verified as a type by comparison with the original literature. Our types were among the first specimens in our herbarium to be barcoded, inventoried, and photographed, a task made easier because, unlike some herbaria, our type specimens are segregated from the rest of the collection. All of our types were photographed in the 1980s and while these photos have since been superseded by digital photographs, I still occasionally refer to them on microfiche to document changes in the specimens (e.g., insect or mechanical damage) or to gather data from specimens that have since been lost (a rare occurrence, thank goodness). Under the direction of retired staff member Ellen Farr, our type collection was one of the first in the world to present both our digital records and images of our specimens online.
When I first started working with our types in 2003, we had about 95,000 type specimens catalogued. Since then, we have added about 20,000 new types for a current total of about 115,000 types, representing a 21 percent increase. Beginning in 2007, with a substantial grant from the Mellon Foundation, the Botany Department hired several contractors to work on the Latin American Plant Initiative (LAPI) (see The Plant Press 10(3): 1, 6-7; 2007). Originally devoted to finding, recording, and imaging type specimens from Latin America, this project eventually grew to encompass all types throughout our herbarium. A series of contractors over the years, notably Shruti Dube, combed through each and every specimen throughout the entire herbarium to find and record all potential types. This was a monumental job as it required not only the verification, inventory, and imaging of each new type specimen, but also the evaluation and re-filing of thousands of specimens that proved not to be types. Since this project began in 2007, we have added about 17,000 new types to the Type Register and the Type Herbarium.
Types*
Diatoms: 400 types
Algae: 5,800 types
Lichens & Bryophytes: 5,400 types
Pteridophytes: 5,600 types
Spermatophytes: 97,600 types (including 16,000 grass types)
*all numbers are approximate
Although the flood of new types has abated somewhat, they continue to come to me. Types are received as gifts from other institutions, specimens come back from loans newly identified as types, and visitors and staff members continue to find overlooked types in the herbarium. All new types are packaged in special type folders that provide better protection than the old type folders (which were notorious for allowing fragments to fall out) but take up slightly more space. All types returning from loans, and all types that come to me with new annotations to be recorded, corrections, or any other kind of work, are being placed in these new folders before being returned to the Type Herbarium. Placing type records and images online has greatly reduced the number of type specimens being loaned, and the number of types present at any particular time has increased.
We have several different type herbaria within the department. The largest are the “pteridophytes” (ferns and lycophytes) and the spermatophytes (seed plants). The smaller type collections of diatoms, lichens, and “bryophytes” (liverworts, hornworts, and mosses) are scattered among a handful of cabinets. Many bulky type specimens (particularly bamboos) are also scattered within the herbarium, simply because the Type Herbarium cannot accommodate them.
Pteridophyte types, now occupying nine herbarium cases, have historically been curated separately from the rest of the vascular plants. This type collection underwent its own radical rearrangement in 2014, shortly after Eric Schuettpelz arrived as the new fern curator. Most of my own work involves the spermatophyte collection. In recent years it became increasingly clear that the collection needed more space. The last time the Type Herbarium was given new cabinet space, in the early 2000s, the collection was decompressed, with room for future expansion allocated within each herbarium case. That space has long since been filled.
In late 2019, 24 additional herbarium cases were added to the Type Herbarium, in addition to the 147 it already occupied. This may seem like a generous 16 percent increase, but it does not quite match the 21 percent increase since 2003. Shifting the specimens to decompress them could have been a simple (if time-consuming) task, but before moving any specimens, I decided to use the opportunity to address the second issue: the new phylogenetic arrangement of the herbarium.
Since the early 20th century, the U.S. National Herbarium has followed a phylogenetic arrangement that is now well over a century old and increasingly archaic. Genera are arranged by numbers originally assigned in 1900 by Dalla Torre & Harms in their Genera Siphonogarum. This reference listed and numbered all known genera and placed them in numeric order following the phylogenetic system of famous German botanist Adolf Engler. US has largely followed this system ever since, with occasional tweaks and new genera squeezed in along the way.
Changes in classification have accelerated since cladistic methodology met molecular phylogenetics and begat an entirely new understanding of plant relationships. The last two decades have seen an upheaval in plant classification at all taxonomic levels. With some of the dust finally settling, particularly at the rank of family, a major overhaul of the entire herbarium is now underway to arrange the flowering plants into an entirely new phylogenetic system. This new family arrangement, spearheaded by Mark Strong, follows the most recent phylogenetic sequence proposed by the Angiosperm Phylogeny Group (APG IV).
The new system does not simply put the existing families in a different order. While some families have proven monophyletic and their circumscriptions remain unchanged (e.g., Poaceae, Melastomataceae, Asteraceae), most families have lost or gained a few genera and some family circumscriptions have changed dramatically. Amaryllidaceae and Liliaceae, long a problematic pair of families, have had their genera reshuffled into each other and into numerous other families. Scrophulariaceae has become a much smaller family, with many of its former members now placed in Plantaginaceae. Some families do not exist anymore. Turneraceae is now included in Passifloraceae and the genera of the former Flacourtiaceae are now distributed among Salicaceae, Achariaceae, and several other families. The result is a modern, up-to-date system that reflects our current understanding of flowering plant relationships and makes phylogenetic sense.
The Type Herbarium has always followed the broad outline of the main herbarium, with one major difference: each type is filed under the name it typifies, not the currently accepted name of that taxon. The arrangement is otherwise similar, with genera arranged numerically and species arranged alphabetically within each genus. If you knew the typified name and its genus number, finding the specimen was easy.
Expanding and shifting the Type Herbarium into new space provided an opportunity to update and reorganize it into the same new phylogenetic arrangement as the main herbarium. From late 2019 to early 2020, I began to shift the type specimens into their new families, and the families into their new herbarium cases. Between assigning genera to their proper updated families, and then physically moving the specimens, this process took about four months. The result is that, while types remain in numeric order within a family, their family assignment will also be required to find them.
In the short term, type specimens are going to be a little more difficult to find. To complicate things further, our understanding of the relationships of genera within the families has also changed. In parallel with the family rearrangements, genera in every family are being re-numbered to reflect these new understandings. The new genus numbers will have two parts, with the first indicating the family number and the second the genus number within that family (e.g., 018-074 for the Annonaceae genus Guatteria). This is an ongoing task in the main herbarium, and most families in the Type Herbarium have not yet been updated with the new genus numbers.
How does one find a type? The first piece of information is the typified name. Knowing that, you will need two additional pieces of information: the current family assignment of the genus and the corresponding genus number. Taxonomic records in EMu (the department’s collections management software) are being updated, but the new family circumscriptions can be found online at the Angiosperm Phylogeny Website. Several of the major online resources like Tropicos, IPNI, and Plants of the World Online have already updated their records to reflect new family assignments. Wikipedia is another surprisingly good source for information on the new classifications. Genus numbers can be found by looking up the name in the taxonomy module of EMu, or by checking the genus number database on the Botany Department’s Intranet (accessible on Smithsonian computers only). Genera are still arranged numerically within each family, and species are arranged alphabetically within each genus. (One exception is Poaceae, in which types have always been filed alphabetically by both genus and species.) To help find the new location of a family, a list has been printed and posted in various locations around the herbarium. I am also available in person to provide assistance in finding type specimens.
The pteridophyte types have always been curated separately from the rest of the vascular plant types. They were formerly arranged phylogenetically, according to the currently accepted name of each type, using an arrangement devised by former curator Dave Lellinger. This arrangement made types difficult to find and to file. Schuettpelz decided to arrange the pteridophyte types alphabetically by genus and species and this has proven to be a much easier arrangement to maintain. The grass types have similarly been filed alphabetically. Based on the demonstrated ease and convenience of finding and filing types in these two groups, the Collections Committee has given its approval to arrange all types alphabetically – a project for the future.
Several tasks remain. First, we are working to update the taxonomic records in EMu with new family assignments and new genus numbers. All type folders in the Type Herbarium need to be updated with the new family assignment and genus number. At some time in the future, types will be arranged alphabetically within each family. Finally, several of our smaller type collections have been neglected for decades, notably the lichen and bryophyte types. Both groups need extensive curation, but we currently lack curators actively working with these groups.
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