JOriiXAL OF THE COLLEGE OF SCIEKCE, IMPERIAL UNIVERSITY TOKYO 



VOL. XXXII., ARTICLE 1. 



Revisio Aceracearum Japonicarum. 



G. Koidzumi. 



{With S3 Platen) 



Introduction. 



In the year 1902, Dr. F. Pax published, in Engler's "Das 

 Pflanzenreich," his excellent monograph of the Aceraceae, in 

 which the genus Acer was divided into 13 sections, comprising 

 114 species in all, besides a large number of varieties and forms. 



Since that publication, new species have been added to the 

 genus from Eastern Asia, especially from the Sinico-Japanese 

 region, augmenting the total number of known species up to 127. 



In 1905, a new section of the genus was proposed by Dr. 

 Eehdepv, based on certain species found in eastern continental 

 Asia, in addition to those of Pax. 



The present monograph deals with Acer found in Japan 

 proper, Loochoo Islands, Formosa and Sachalin. Based on the 

 results of careful examinations and revisions of each species, I 

 have attempted to present a new systematic arrangement of the 

 genus on the principle of bringing out as far as possible the 

 phylogenetic relations of the members. 



The vernacular names of every species are taken principally 

 from the works of Prof. J. Matsumura^ and Prof. M. Shirai.' 



The present work was taken up at the suggestion of Prof. 

 J. Matsumura, to whom I beg herewith to express my grateful 

 thanks for the many acts of kindness renderd me during my 

 studies. I am also under great obligation to Prof. M. Shirai 

 who helped me in many matters regarding the literature. Further 

 to Dr. Y. Shirasawa, Prof. G. Yamada, and Mr. T. Kawakami 

 of the Formosan government, I am much indebted for the valuable 

 material placed at my disposal. 



1- Bm&^^M- ed. 3. (1897J. 



2. u^mm^mm- {1908). 



