286 



Mycologia 



nudum) ; Yamada in Omori, J. & Yamada, G. Shokubutsu Byo- 

 rigaku (Plant Pathology) Tokyo, Hakubunkwan, M. 37, 1904, 

 p. 306-308, fig. 38 (Japanese). 



Gymno sporangium Yamadai Miyabe ex Ideta in Nippon Shoku- 

 butsu Byorigaku (Handb. PI. Diseases in Japan) ed. 3, Tokyo, 

 Shokwabo, M. 36, iv, Apr., 1903 (nomen subnudum) ; Miyabe 

 in Ideta ditto ed. 4, pt. 2: 471-474, fig. 174. M. 44, 191 1 

 (Japanese). 



Description by G. Yamada and K. Miyabe combined : 



I. Aecia hypophyllous, on more or less thickened, reddish-brown 

 spots, cylindrical, thick, 0.4-0.5 mm. in diam., 5-8 mm. high; 



peridium fulvous, splitting into a fine lace-like network ; peridial 

 cells narrow and elongated, 60-80 x 20-24//,, inner wall smooth, 

 outer wall slightly verrucose, side wall tuberculate with short 

 papillae and never making elongated ridges ; aeciospores subglo- 

 bose or polygonal, 16-24 /m in diam., wall thick, brown, finely ver- 

 rucose, the pores 8. scattered. 



On Pyrus Malus (Apple), Pyrus spectabilis, and P. Toringo. 



III. Telia caulicolous, from a perennial mycelium, appearing on 

 reddish-brown, spheric swellings of the host stem, of somewhat 

 shining appearance, disclosed by the rupturing of the cork in 

 irregular fissures, flavo-rubescent, flat, petal- or tongue-shaped, 

 irregular, deep-fuscous when desiccated ; teliospores 2-celled, ob- 

 long, broad-ellipsoid, obovoid or clavate, upper cell always larger, 

 frequently with thick-walled, obtuse papilla at the apex. 40-50 x 



15-22 [A. 



On Junipcrus chinensis and /. chinensis var. procumbens. 



Apple culture of the northeastern territories has been menaced 

 by the disease. In Sapporo, Hokkaido, it made its first appear- 

 ance in 1902 with the introduction of /. chinensis, carrying the 

 fungus from the south. According to Ideta (1. c. ed. 4 p. 472), 

 Miyabe first found in 1904 the connection of apple rust with this 

 particular Gymno sporangium inhabiting on the juniper stems. 

 The aecial stage develops in July and August causing discolora- 

 tion of apple leaves, which frequently results in defoliation. 

 The telial stage appears on the juniper in April or May in the 

 main island, and in May or June at Sapporo, Hokkaido. 



