A METHOD IDENTIFYING THE SPECIES WITH THE ROOT IN DIOSPYROS KAKI L. fil., D. LOTUS L. AND D. VIRGINANA L.

Abstract

In this report, a method of identification of species by means of the color reactions in the water extracts of the bark is suggested. The bark of the root was sliced off with a sharp knife. The exposed surface of the root changed into yellowish color very quickly and intensively with Lotus, moderately with virginiana and the least with kaki. The sliced bark was weighed and immersed in separate beakers containing a volume of distilled water of fifteen times as much as the weight of the bark to provide water extracts. After two to twelve hours'extraction, the color of the solution in the test tube was deep yellowish brown in D. Kaki, yellow orchre in D. Lotus and pale yellow in D. virginiana (“A”in the Plate). The hydrogen ion concentration of the extracts was 5.39, 5.91 and 5.65 respectively. No apparent change in color occurred in addition of any acid.An addition of a small amount of alkaline solution, however, gave a sudden change to the color of the original extracts, showing a purple garnet color in kaki, reddish violet in Lotus and pink in virginiana (“C”in the Plate). This fact seems to suggest that there exists certain coloring matter in the root of these Diospyros species, which is yellowish in acidic and reddish in alkaline solution. In addition of zinc chloride or copper acetate solution there were also observed different color reactions accompanied with characteristic precipitates (“D”, “E”, “F”and“G”in the Plate). Sections treated with alkaline solutions revealed that the coloring material distributed intensively in cork layer and very lightly in phloem and xylem tissues of kaki root. In Lotus and virginiana roots, the coloring material seems to exist in fair amount in xylem and phloem portions and in relatively small amount in periderm.