What is “FLORISTICS”?
Floristics (the Floras program) is basically a study of what plants grow where. The products of floristic work may be simple checklists of species that grow in given areas, or they may be books (called "floras") with much detail about the plants in given areas. It's often difficult to determine what names go with what species, although scientific names are applied in a precise, rule-oriented way that's intended to ensure consistency. Further, because of the way nature operates, distinctions between species may be difficult to discern, and further still, botanists often differ in their concepts of species and genera.
How is the herbarium used in floristics?
The principal resource in floristics research is the herbarium – the hundreds of thousands of plant specimens collected over the years and accessioned in permanent form. Each specimen is labeled with information about where and when it was collected. In a perfectly complete herbarium, it would be possible to simply survey the specimens and prepare a floristic account for a given area. But of course, the number of species in any given area is constantly changing as plants become extinct when their habitats disappear or as “alien” plants are introduced into areas where they are not native. For a study of a relatively small area, a research botanist might go in person and, over several seasons, record all of the species that grow in that area, but a floristic study usually involves both field and herbarium surveys.
Herbarium collections provide important documentation about plant species that grow in the study area. Collecting the plants and pressing, labeling, mounting, and filing the specimens may be tedious, but it is the basis of floristics. As in all sciences, replication is critical, and the existence of herbarium specimens means that other botanists can survey the herbarium and arrive at the same floristic conclusion. Examination of herbarium collections can provide updated identifications of specimens, eliminating the need to return to the study area and recollect. Equally important, having a specimen at hand allows a botanist to repeatedly study it under a lab scope, providing a more refined understanding of the plant’s identity. And finally, herbarium collections are significant because, as our natural landscape is overtaken by commerce, housing, and agriculture, the specimens can provide verification that a particular species actually did once grow in a given location. Also see Importance of the Herbarium. Google search for "What is a herbarium?"
How is the library used in floristics?
Three ways to identify a plant you don't already know: (1) compare with already-correctly-identified specimens in the herbarium, (2) ask an expert nearby, or (3) ask for help from literature via published keys or photos, etc. The BRIT library is replete with identification literature for North America, South America, Africa, Australia, Japan, Russia, Czechoslavia, France, Iran, Hawaii, Taiwan, etc., on and on. So much literature. Of course, if one suspects that the unknown plant in hand might not be native, it's extremely helpful to know what region of the world it came from, so to be able to know where to begin in the potentially efficacious but voluminous literature.
What is “SYSTEMATICS”?
Evolutionary relationships among species.
Systematics includes research toward an understanding of evolutionary relationships among species (and among genera and families, etc.), as inferred from information about plant structure, chemistry, or genes. Many systematists throughout the United States and the world are currently using molecular evidence (usually sequences of the components of DNA molecules) as the basis for this kind of research. BRIT researchers primarily work with morphological evidence (structures of the flowers, fruits, stems, leaves, and roots, etc.), although they sometimes collaborate with others who are doing molecular research. Results of evolutionary research in systematics are commonly presented as evolutionary trees –- branching diagrams showing hypotheses of plant ancestry.
Recent systematics research has tended to suggest and support revised concepts of the composition of genera. BRIT botanists have been involved with some of this, particularly with the ragworts (Barkley) and asters (Nesom) of the sunflower family but our research is mostly toward species definitions, based on the wealth of morphological data available through work in the field and herbarium.
Discovery of new species.
One of the most exciting parts of research in systematics is the discovery of new species that have long existed in nature but have never been recognized for their distinctive traits. In a few parts of the world, such as Papua New Guinea, significant areas of the natural landscape and flora simply have not been explored and catalogued. In North America, most of the species still left to be discovered are rare, exist in specialized habitats where collections have not been made, or else the distinctions between a previously unrecognized species and close relatives are subtle and botanists have not seen the difference. In the latter case, two species (or more) often are identified as being part of just one ..... until the differences are finally recognized and new species is named. Look over the many new species recently described by BRIT researchers.
Definitions of species.
Systematics also includes research towards better definitions of species, including their distinctions from closely similar ones. Because study of a large number of plants from over a broad geographic range enables an understanding of variation within a single species, the value of the herbarium is central. A researcher in systematics commonly relies first on herbarium collections and then goes into the field to make first-hand observations to solve critical problems.
How is "botanical nomenclature" related to systematics?
Application of scientific names is based on a set of rules guided by the ‘principle of priority’ – the correct name for a species generally is the first one published following established guidelines in the International Code of Botanical Nomenclature. Although a single species may have been given more than one name during the course of centuries, the oldest plant names accepted as valid today are those published in the book Species Plantarum by Carl Linné (Linnaeus) in 1753. To set the concept of a scientific name, a herbarium specimen must be associated with the name at its publication. Thus, to know exactly what species a particular name refers to, it is necessary to examine the single plant specimen (or duplicate of if), referred to as type specimen, upon which the name is based. This can be a difficult task, especially if the species was described in previous centuries and the specimens those botanists had in hand are no longer available.
How is the library used in systematics?
Because the "principle of priority" is central to botanical nomenclature, research regarding correct names must take into account literature dating back to 1753. The extensive collection of historical botanical literature in the BRIT library is a critical and necessary resource.
Also see What kinds of botanical research are done at BRIT?
