Tanaka: Xi:vv Japanese Fuxgi 283 



Ideta (under supervision of Miyabe) gives the spore characters 

 as follows : " Teliospores 2-celled, f usoid, 45-70 x 20-25 p., long- 

 pediceled." (hi Nippon Shokubutsu Byorigaku ed. 4, pt. 2: 470. 

 M. 44, 191 1. Japanese.) 



Notes: Sydow first described Gyumosporancjiiim japonicuni 

 from the specimens on the branch of Jiinipcnis chincnsis collected 

 by Shirai at Koniaba, Tokyo (/;; Hed\vi;j^ia, Beibl. 38'' : ( 141 ) ■\Liy- 

 June, 1899), and later. Shirai succeeded in producing RoestcUa 

 (R. korcaensis) on Japanese pear leaves by inoculating with some 

 mixed forms of Gymnosporangiuin found on the leaves and stems 

 of Junipcrus chincnsis, and which he called G. japonicum (in 

 Zeitsch. f. Pflkr. 10^: 1-4, pis. 1-2. Apr., 1900). These results 

 apparently induced many Japanese pathologists to believe that G. 

 japonicum is the causal organism of the devastating Japanese pear- 

 rust, though Miyabe clearly defines that G. asiaticuui occurs only 

 on the leaves. The first comprehensive description of G. asiaticwn 

 given by Yamada also limits the occurrence of the telia to the 

 juniper leaf only, and Yoshino later showed that the pear-rust is 

 caused only by the leaf-inhabiting form of Gymnosporangium (G. 

 asiaticum) in the Kyushu island, and not by the stem-inhabiting 

 form which he never found existing in the island (in Shokubutsu- 

 gaku Zasshi, Bot. Mag., Tokyo, 19^'- : 167-168. M. 38, vii, July, 

 1905. Japanese). Ideta also describes the telial stage from the 

 leaf-inhabiting form only, though he was liberal in bringing the 

 name G. asiaticum into the synonymy with G. japonicum in his 

 latest description (1. c. ed. 4, pt. 2: 467, 469-470. 191 1). 



Despite the existence of the valid name Gymnosporangium asi- 

 aticum applied to the form on the juniper leaves, Sydow renamed 

 the leaf-inhabiting form as Gymnosporangium haracanum, based 

 upon the material collected by K. Hara from Mino province (in 

 Ann. Mycol. lo^ 405. Aug., 1912). Using the fresh material 

 taken from the juniper plant upon which Sydow's type was col- 

 lected, Hara succeeded in producing pear-rust by inoculation (in 

 Shokubutsugaku Zasshi 27^^°: 348. T. 2. vii, July, 191 3. Japa- 

 nese). At the same time, Ito succeeded in producing rust on 

 Photinia viUosa by inoculating the stem-inhabiting form which he 

 determined to be G. japonicum Syd. (in Shok. Zass. 27^-^: 221- 



