Vascular Plant Taxonomy - Bio 3400 - at Utah State University

In talking about taxonomy, there is a tendency to use recognition, identification, and classification as synonyms, (i.e., as words that have the same meaning), but they are not. The goals of this class are enable you to recognize 50 families, identify species, and understand the principles and practice of plant classification. What is the difference between the three processes?  

Recognition means looking at a plant and realizing that it is the same species as a plant one has seen earlier; one can name it because one is already familiar with the species. Recognition is a very useful skill, so long as one stays in the same part of the world. The further you move, the less help it is. Moving from Logan to St. George will bring you up against numerous species you will be unable to recognize because you have not seen them before. In many instances you will be able to recognize to what family they belong because the same family occurs in northern Utah. In other words, recognition is a matter of memory work. It is great to be able to recognize lots of plants, but if that is all you can do, you are limited as to where you can function usefully as a taxonomic assistant. Graduates of a plant taxonomy course are expected to be more versatile. 

Identification involves working out the name of a plant you do not recognize. In this class you will learn how to use a typical flora, R.J. Shaw's Vascular Plants of northern Utah, for this purpose. Keying out a plant is simple in theory; in practice things are a bit more complicated. First, there is a lot of terminology involved. Second, plants vary, sometimes in ways that the writer of a key did not anticipate. And then there are always the mistakes that are made by key writers and key users. NO key is perfect; certainly not the keys to grasses I wrote for the northern Utah flora. And everyone I know sometimes makes mistakes in keying. Nevertheless, so long as there is a vascular plant flora for a region, graduates of Biol 3400 should be able to use it to identify plants they have never, ever, seen before. 

The ability to identify plants means you would be useful as a botanist in any part of the world because you could work out the names of the plants that grow in these locations, so long as some has already classified them.  Soon you will learn to recognize some of them, but this will take a little time. We should also be realistic; there are some weird plant families that will floor you when you first meet them, but if you are prepared to work at it, you should be able to use any vascular plant flora. 

Classification differs from both recognition and identification. Both these two process require that the plants have already been assigned a place in a classification, i.e., they have already been assigned to a group. Classification is the process of determining what constitutes a group and, as a corollary, determining to what group a plant belongs. By and large, only professional taxonomists, and not all of them, classify plants. I have done some classification. For instance, I have published a paper in which I argued that several species that had been classified as species of Stipa should be treated as species of Nassella (Barkworth, M.E. 1990. Nassella (Gramineae, Stipeae): Revised interpretation and nomenclatural changes. Taxon 39:597-614). 

Another aspect of classifying involves realizing that one is looking at plants that do not fit into any existing classification making it necessary to describe a new group (such as a new species) and provide a name for it. Frank Smith, a local field botanist has been responsible for describing over a dozen species from western North America. 

What do non-classifying taxonomists do? Many conduct the basic studies that contribute the kind of information that helps improve existing classifications. The next topic addresses what is meant by a good classification and, by implication how one determines whether a new classification is an improvement or not. 

To summarize: Classification has to precede naming, identification, and recognition. Recognition relies on memory; identification requires understanding of plant parts so that keys (or other tools) can be used. Nowadays, classification requires understanding the biology of the plants concerned, but Linnaeus classified hordes of plants in a manner that took no account of their biology. This approach is still considered reasonable when dealing with some groups, but biological understanding always aids in developing biological classifications.