The Japanese sundews that have previously been collectively called D. indica L. (especially after the influential Flora of Japan, Ohwi 1965:492) are being split up. Various authors (e.g., Watanabe 2013) are trying to re-establish or create one or two additional species assumed endemic to Japan, following the contemporary trend to recognize a number of segregate taxa in Drosera sect. Arachnopus (Greek for “spider leg”), the group that contains D. indica. Previous research (Schlauer et al. 2017, 2018, 2019) has demonstrated a rather unexpected diversity in the naphthoquinones that are characteristic for the different species now recognized in this group. While a few Australian species contain ramentaceone (7-methyljuglone), most contain the regio-isomer plumbagin (2-methyljuglone). So far, only D. indica s.str. (accessions from Asia and Africa have been investigated) contains both isomers in the same plant. The morphological diversity found in Japan thus prompted a chemical investigation, the results of which are reported here.
Keywords: Japanese Spider Leg Sundews, Drosera, Phytochemistry, Naphthoquinones, Chemotaxonomy
Jan Schlauer and Siegfried R. H. Hartmeyer and Irmgard Hartmeyer. 2019. Quinone patterns and identification of Japanese Spider Leg Sundews (Drosera Sect. Arachnopus). Carniv. Pl. Newslett. 48(4):161-163.
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