Atsumi OZAWA, Nana OOMIZO, Rieko FUJINAMI, Ryoko IMAICHI, and Hajime IMAI

Faculty of Science, Japan Women's University, Bunkyo, Tokyo 112-8681, Japan

(Received May 31, 2010; Accepted August 18, 2010)

Reflectance, transmittance and absorbance spectra were observed of Hydrobryum japonicum, a kind of Aquatic angiosperm, over the wavelength range from 300 to 780 nm. Three remarkable peaks were observed at 380, 430, and at 680 nm in the absorbance curve, which were assigned to the two pigments flavonoid and chlorophyll. The functions of these pigments of making photosynthesis inevitable for the botanical activity and of protecting the plant from the heat given by the sunlight were discussed.

Key words: chlorophyll, spectroscopy, flavonoid, optical absorption, ultraviolet rays