TAXONOMIC PRINCIPLES ]3 



ecological-genetic classification (Grant, 1960). Table 2-1 shows the 

 characteristics and relationships of these informal groups. These and 

 similar categories are becoming increasingly common in the sys- 

 tematic literature. They are useful additions to the vocabulary in that 

 they enable the experimental worker to describe more accurately the 

 kinds of biological entities with which he is concerned. Information 

 conveyed in this form avoids any cumbersome explanatory extra- 

 polations to the formal categories. In addition to the experimental 

 categories shown in Table 2-1, many additional informal descriptive 

 terms have been proposed by numerous workers (Camp and Gilly, 

 1943; Grant, 1960; and others). 



BIOCHEMICAL CATEGORIES 



With the accumulation of chemical data from various plant 

 groups it seems likely that some serious attempt will be made to erect 

 a special nomenclature to deal with those categories so delimited. 

 Tetenyi (1958) has already proposed a series of infraspecific categories 

 such as chemouar, chemoforma, and chemocultivar, and so on to 

 designate appropriate races or forms of chemically defined taxa. We 

 are inclined to agree with Lanjouw (1958) "that chemical strains or 

 varieties formed in the wild should be treated as ordinary infraspecific 

 units"; however, we doubt that these groups, unless accompanied by 

 sufficient morphological divergence, should bear formal names accord- 

 ing to the International Code of Botanical Nomenclature. It is al- 

 ready apparent that chemical components may show variation just as 

 do morphological features, and any effort to encourage a formalized 

 nomenclature would only invite a deluge of names which would 

 further extend the lists of synonymy and in other ways increase the 

 nomenclatural burden. For the present, it appears wiser to develop 

 informal descriptive categories, much as has been done by the cyto- 

 genetical workers. As an example, one could speak of the chemical 

 races of a given taxon using the distinguishing constituents as adjec- 

 tives—thus, cyanogenetic race or acyanogenetic race, and so forth. 

 There seems to be little merit in a formal system along the line sug- 

 gested by Tetenyi (1958) and Mansfeld (1958). If we are to believe in 

 the biochemical individuality within Homo sapiens (Williams, 1956), 

 there would be nearly as many formal "varieties" or forms as there 

 are people. 



The field of biochemical systematics is too poorly developed 

 to predict accurately its long-term effect on plant taxonomy. We are 

 certain that it will add greatly to the data with which to develop 

 further our system of classification. However, any changes in the 

 nomenclatural system will surely be incidental to its more important 



