System of color wheels for streptomycete taxonomy.

In the sundry systems of streptomycete taxonomy, color of the sporulating aerial mycelium is frequently employed as a systematic criterion. Color series, each containing species of similar spore colors, are generally erected; however, the range of colors encompassed within a series is often not clearly delineated by the usual word description. Therefore, a system is proposed in which the color content of each series is more accurately defined by means of color tabs. Seven spore-color series are recognized (i.e., red, gray, yellow, blue, green, violet, and white), each of which is represented by a color wheel that displays the range of colors included therein. By comparing spore colors with the color wheels, unclassified isolates can readily be assigned to appropriate color groups.