350 THE FUNGI WHICH CAUSE PLANT DISEASE 



Chrysomyxa Unger (p. 341) 



III. Teliospores formed of a series of superimposed cells, of 



which the lower are sterile, 

 ^■^ ^ forming flat or slightly ele- 



vated, orange or reddish, 

 waxy, crusts. Germina- 

 tion of the teliospore by a 

 promycelium from each 

 cell, which produces mostly 

 four basidiospores. 

 C. abietis (Wal.) Ung. 



Fig. 254. — Melampsoropsis rhododendri, section Tolio c\r\\\r Tf frirmc 

 through telium. After De Baiy. ^^"^ °"'y- " ^"^^^ 



yellow spots on spruce 



leaves and the basidiospores seem able to infect the same host. 



European. 



Cronartium Fries (p. 341) 



O. Pycnia deep-seated, broad and flat. 



I (=Peridermium). iEcia erumpent, inflated. Peridium mem- 

 branous, rupturing at the sides rather than above, 2-4 cells thick, 

 outer surface smooth, inner verrucose. Spores ellipsoid; wall 

 colorless, coarsely verrucose with deciduous tubercles, except a 

 smooth spot on one side. 



II. Uredinia somewhat erumpent. Peridium moderately firm, 

 rupturing above, upper part evanescent; peridial cells isodiametric. 

 Spores borne singly on pedicels, globoid to ellipsoid; wall nearly or 

 quite colorless, echinulate, pores obscure. 



III. Telia erumpent, at first arising from the uredinia, the 

 catenulate spores adhering to form a much extended, cylindrical or 

 filiform column, homy when dry. Spores oblong to fusiform, 

 1-celled; wall slightly colored, thin, smooth. 



Five American species are recognized by Arthur.** 

 All known secial stages are Peridermiums on stems of conifers. 

 C. ribicola F. de Wai.^^-^' »' 



O. Pycnia caulicolous, scattered, honey-yellow, forming minute, 

 bladdery swellings. Spores hyaline, ovoid to elliptical, 1.9-4.7 /*. 



