METHODS OF PRESENTATION OF CRUDE BIOCHEMICAL DATA FOR SYSTEMATIC PURPOSES, WITH PARTICULAR REFERENCE TO THE GENUS BAHIA (COMPOSITAE)

Abstract

Ellison, W. L., R. E. Alston, and B. L. Turner. (U. Texas, Austin.) Methods of presentation of crude biochemical data for systematic purposes, with particular reference to the genus Bahia (Compositae). Amer. Jour. Bot. 49(6): 599–604. Illus. 1962. — A partial biochemical “profile” (as determined chromatographically for selected constituents) of a given species is compared with that of other species in the genera concerned. The chemical affinities of each of these pairings are expressed in percentages along the radii of a circle. The points are then connected so that these affinities are shown in the form of polygons. Such graphs can be looked upon as pattern configurations purporting to show biochemical similarities or differences between and among species. Graphic information of this nature can be used to supplement those data obtained from morphological studies. In addition to affinity values and polygonal diagrams, chromatographic data can be presented in the form of synthetic numerical indices which permit quantitative expression of systematic relationships among taxa of any taxonomic rank. This relationship is expressed in a fashion that presumably gives equal weight to both similarities and differences. These techniques were applied to a systematic evaluation of relationships in Bahia and related genera. Several taxonomic dispositions were suggested, the most striking being the treatment of Bahia as composing 2 phyletic series, the Alternifoliae and the Oppositifoliae, and the suggestion that Bahia oppositifolia be treated as a separate genus, Picradeniopsis.