Eleutherococcus vs. Acanthopanax

IN RESPONSE TO a growing interest in the use of ginseng, chemists and physicians have investigated the chemistry and the physiological activities of crude drugs prepared from the roots and bark of Panax ginseng C. A. Meyer and other araliaceous plants.Included in these studies have been the Chinese drugs known as Wu-chia-p'i, which are prepared from the bark of different species of Eleutherococcus.The investigations have resulted in the isolation of sitosterol glycosides from Eleutherococcus senticosus (Rupr.& Maxim.)Maxim., and in the discovery of similar physiological a rag induced by these glycosides and the ginsenosides of P. ginseng (Brekham, 1969; Anonymous, 1976).Because of these similarities, extracts from ee of Eleutherococcus have been used as substitutes for ginseng.Communicating the results of the chemical and physiological studies has often proved difficult and confusing since species of Eleutherococcus have sometimes been included in the genus Acanthopanax, and the nomenclature has been unstable.A summary of the taxonomy of these two genera and necessary nomenclatural changes are presented here in order to clarify this situation and to provide a more stable and less confusing nomenclature.A survey of the pertinent literature indicates that Eleutherococcus Maxim.(typified by E. senticosus) is the earliest validly published name for the genus that some authors have called Acanthopanax (Decaisne & Planchon) Miquel (typified by A. spinosus (L.f.) Miquel).Decaisne and Planchon (1854) used Acanthopanax as a subgenus of Panax L., and later Miquel (1863) raised the subgenus to generic level.Harms (1894) combined A canthopanax and Eleutherococcus, but he used Acanthopanax as the generic name and recognized Eleutherococcus at sectional rank.Harms's treatment has been followed by Rehder (1940, 1949), Li (1942), Bere satey authors, and floristic botanists in China and Japan.However, in 1924 Nakai recognized both Acanthopanax and Eleutherococcus as distinct genera, and his treatment has been adopted by Poyarkova (1973 The characters utilized by Poyarkova to separate the two genera are ''ovary 2-locular, styles 2; fruit with 2 stones; petioles glabrous or scarcely pubescent, articulate with rachis'? for Acanthopanax, and ''ovary 5-locular, styles 5, fruit with 5S stones; petioles not articulate, densely pubescent'' for Eleutherococcus.These characters may hold for distinguishing the two species (one placed in each genus) that occur in the relatively limited area of the Soviet Far East, which constitutes the periphery of the generic range, but they are of no generic value when species from over the entire geographic range are considered.Even for the small number of Japanese species, Nakai (1924)