NOTES ON SOME SPECIES OF GYMNO- 

 SPORANGIUM IN COLORADO 



Ellsworth Bethel 

 [With Plate 48, Containing 2 Figures] 



Colorado possesses an unusually large number of interesting 

 cedar rusts. Nine distinct species are recognized (ten with the 

 new species described below), which is about one third the 

 number of the telial forms known to occur in the United States. 

 These have been brought to notice through the careful investiga- 

 tions of Dr. Arthur and Prof. Kern, who have visited the state 

 twice in search of rusts, supplemented by the work of the writer 

 in making collections and field observations for the purpose of 

 connecting them with their roestelia stages. Of the nine species, 

 five have been connected with their roestelia stage through the 

 culture work of Arthur and Kern, and, with telial material of 

 Gymno sporangium juniperinum (L.) Mart, collected this spring, 

 it is hoped that its connection with Roestelia fimbriatum Arthur 

 will be established, since abundant field observations point to 

 this relationship. 



There is only one known unconnected Roestelia, that of the 

 pear and quince, which is probably not related to any of the 

 three unattached species, namely, G. durum Kern, G. speciosum 

 Peck, and G. multiporum Kern, unless it be G. durum. For the 

 purpose of getting culture material of these three unattached 

 species, and especially to gather information regarding the pear 

 and quince rust, the writer made a short visit to the southwestern 

 part of the state during his spring vacation last month. Nothing 

 could be learned of the pear rust, as the trees had been cut down 

 some years ago on account of the disease. Good telial collec- 

 tions were made of G. durum and G. inconspicuum Kern (al- 

 ready connected by culture with Roestelia Harknessianoides 

 Kern). 



156 



