594 



COMPARATIVE MORPHOLOGY OF FUNGI 



As in the other orders, the probable relationships between the families 

 and genera have been schematically represented below. 



In conclusion there may be briefly cited from the four families some 

 interesting, pathologically important species, whose nomenclature, 

 because of the various estimates of their biological importance, is always 

 in a state of flux. The gametophytes of the Coleosporiaceae, Melamp- 

 soraceae and Cronartiaceae occasionally produce pandemic diseases of 

 conifers. Their aecidia are designated as blister rust, and earlier, when 

 their heteroecism was unknown, were grouped together in the single genus 

 Peridermium. In the gametophyte, the species of Coleosporium live on 



UREDINALES 



PUCCINI ACEAE 



Rayenelia 

 Hemileia Uromycladium 



Puccinia Gymnosporangium PhragmidiumNy Triphragmium Kuehneola Gymnoconia 



Zaghouania 

 Cystopsora 



Endophyllum 



Kunkelia 



CRONARTIACEAE 



Cronartium 

 Chrysomyxza 



MELAMPSORACEAE 



Calyptospora 

 Thecopsora 

 Pucciniastrum 

 Melampsoridium 



Melampsorella 

 Hyalopsora 



Mileeina 

 UredinopBis 



COLEOSPORIACEAE 



Coleosporium 



Goplana 



Gallowaya 



Diagram XXXVIII. 



pine needles; their sporophytes are specialized on different angiosperms 

 as that of C. Sonchi on Sonchus. C. Senecionis and C. Campanulae, besides 

 growing on their normal sporophyte hosts (Senecio and Campanula 

 respectively) , also attack representatives of exotic families. In Chrysomyxa 

 the micro- form, C. Abietis lives on fir needles, in the gametophyte; the 

 heteroecious eu- form, C. Rhododendri lives on Rhododendron in the 

 sporophyte. Cronartium ribicola, the white pine blister rust, has its 

 gametophyte on the bark of Pinus Strobus and other white pines, the 

 sporophyte on Ribes. C. asclepiadeum causes blister rust of the pine, 

 while its sporophyte is plurivorous (p. 592). Melampsora pinitorqua 

 causes a disease of pines (gametophyte on Populus) and Melampsorella 



