The complete scientific name of a species consists of a generic name with a specific epithet, the authority for the name, and bibliographic data indicating where the name was published. The generic name and specific epithet are latin words and agree in gender and grammatical case. In typescript/print they should be italicised and in manuscript they should be underlined (underlining is the instruction to a printer to set the type in italics). The generic name starts with a capital letter and the specific epithet with a common letter.

Pride of Barbados has the scientific name Caesalpinia pulcherrima (L.) Sw. Observ. Bot. 166. 1791. The generic name is Caesalpinia (named for Andrea Caesalpini (1524-1603), Italian botanist) and the specific epithet is pulcherrima (= beautiful). In this case, the authority is in two parts - the species was named by Linnaeus (L.) but reassigned to the genus Caesalpinia by Peter Olof Swartz (Sw.). Swartz's name change was published in 1791 on page 166 of his book Observationes Botanicae.

Linnaeus had named it Poinciana pulcherrima in 1753 on page 380 in the first volume of his Species Plantarum (Sp. Pl. 1: 380. 1753). Linnaeus' name is the basionym (base name) since his species concept was not changed by Swartz. P. pulcherrima is a synonym for C. pulcherrima - both names have been used for the same species.

Other common names for this species include: Dwarf Poinciana, Barbados Flowerfence, Paradise Flower, Red Bird-of-Paradise, Ohai-Ali'i (in Hawaii), Tabachin (Mexico), Francillade (Haiti), Clavellina (Dominican Republic), Feng Huang Ch'Ang (China), Chana (Java), Jambul merak (peacock feather) (Malaya).

This plant is always called Caesalpinia pulcherrima (or P. pulcherrima) whatever the country (or the language spoken). That is why we use scientific names - they are standardised and International. Common names vary and, worse, the same common name is often used for more than one plant species, e.g. ackee in Barbados and Jamaica.

All four parts of the scientific name are rarely used outside of taxonomic works. However, in a scientific paper/essay/project report, the authority should be quoted on first mention. Thereafter, the generic name and specific epithet are sufficient and, providing it is not confusing, the generic name can be abbreviated to a single capital letter.

The specimens used by plant taxonomists are housed in Museums and Herbaria of Universities and Research Institutes. The largest collections are in major cities of developed countries of the north.

The focus of this, and the next lecture, is on green plants. However, the principles are the same for members of other major groups. Plant specimens are stored in herbaria. Most are pressed/dehydrated and mounted on herbarium sheets with a label identifying the taxon, information on where and when it was collected and by whom. Fruits and other fleshy parts may also be stored in a spirit collection, i.e. in jars with alcohol, FAA (formalin-acetic acid-alcohol), or other preservative solution.

The following are links to the web pages of some major herbaria:

The New York Botanical Garden Herbarium (NY)
The Missouri Botanical Garden’s Herbarium (MO)
The Botany Department, The Natural History Museum, London (BM)
Herbarium of the Royal Botanic Gardens, Kew (K)
L'Herbier du Museum National d'Histoire Naturelle, Paris (P)
The Herbarium of the Botanical Museum Berlin-Dahlem (B)
Harvard University Herbaria (A, AMES, GH, & NEBC)
Australian National Herbarium (CANB, QRS)

For obvious reasons, taxonomists have traditionally been located with the major research collections in the developed countries. This is despite the fact that species diversity is greatest in the regions closest to the equator, especially within the equatorial rainforests. The discrepancy in numbers of taxonomists between north and south is decreasing. However, this is not only due to an increase in numbers in the tropics but is also a result of a decrease in the number of taxonomists in the older centers.

The products of traditional plant taxonomy are Floras and Monographs. A flora is the result of a study of the plant life of an area, it consists of descriptions of families, genera and species found in the study area and identification tools (normally, dichotomous keys). A typical monograph lacks the area focus and results from a study of all the members of a taxonomic group (commonly a family, genus or section).

Two examples of floras are Flora of North America and Flora Mesoamericana both of which have on-line versions. These are both large scale projects involving collaboration between many taxonomists. Floras may be restricted to smaller areas and a subset of the plants, e.g. Ferns of Barbados.  

How do they do it?

First, gather specimens. These will be in herbaria or growing in the field and can be obtained "on loan" from other herbaria and/or by field collection. It is important that the specimens accumulated adequately reflect the variation in the taxa under consideration (within the study area - flora/ throughout their range - monograph). Inadequate sampling may result in poor descriptions and classification decisions. Which, in turn, is one cause of the proliferation of synonyms.

Taxonomists work by making comparisons. In its "simplest" form this is the shuffling of herbarium sheets into piles of different taxa based on morphological similarity. The biological species concept cannot be applied to dead plants! At another level, the comparisons are made with type specimens.

Taxonomists will also conduct bibliographic studies to discover previous authors species concepts, names applied to each taxon, locations of types and, in the case of a flora, the species previously recorded from the study area.

Descriptions will be writen of each taxon. If the taxon is being described for the first time, a description in Latin is required. [Example - 'Easter lily cactus'.] Identification keys will also be prepared, normally these will be dichotomous. 

Nomenclatural decisions will be made. In a monograph, this will involve accounting for all the names existing before the current study. New names will be created as needed. The taxonomist should ensure that the names conform with rules of nomenclature including the principles of one name per plant, priority and correct Latin (see above). The rules are found in the International Code of Botanical Nomenclature (ICBN).

Areas covered by the ICBN include:

• The categories to use

• Forms and spellings of names

• Selecting among competing names

• Formats for bibliographic citations

• Process for establishment of names and new species

The final work will include citations of the literature consulted and cited, and the specimens examined (or a representative sample) and the herbarium in which they may be found.