THE RUSTS OF NOVA SCOTIA. FRASER. 333 



before the spores are shed and burned. However, little injury 

 is done by these f uiigi and no measures of control are necessary. 



Peridermium Peckii and Caeoma Abietis-canadensis Farl. 

 occur on the leaves of the hemlock (Tsuga canadensis) , but 

 they are not very common nor of much importance. Necium 

 Farlowii, which attacks the leaves and young twigs, is more 

 injurious. The infected twigs soon curl up and die, but the 

 fungus is rare and therefore of little importance. 



The leaves of the spruces (Picea) are attacked by the aecial 

 stages of the Ledum rusts (Melampsoropsis ledicola, M. 

 abietina) and though sometimes the} 7 are very richly infected 

 yet no serious injury seems to be done. The destruction of the 

 Ledum plants in the neighbourhood of the spruces would 

 probably be effective in controlling these rusts. The spruce 

 cones are also attacked by the aecial stage of the Pyrola rust 

 (Melampsoropsis Pyrolae). 



The aecial stages of the willow and poplar rusts (Melamp- 

 sora Bigelowii, M. Medusae} are found on the larch (Larix 

 laricina} but they are rare and of no economic importance. 



Rusts of Deciduous Trees : The leaves of the poplars and 

 willows are attacked by the uredinial and telial stages of 

 Melampsora Medusae and M. Bigelowii respectively, and those 

 of the birches by Meldmpsoridium Betulae, but the injury is 

 not serious and does not usually call for control. The burning 

 of the infected leaves in the fall would probably be helpful in 

 checking the rusts. 



The aecial stage of some rust of the genus Gymno- 

 sporangium has been collected 011 the fruit of the wild plum 

 ( Amelanchier) , and probably the alternate host is the low 

 juniper. It is probably rare and of little importance. In the 

 United States the aecial stages of some, species of the genus 

 Gymnosporangium attack the leaves of the cultivated apple, 

 but these have not been reported from !N"ova Scotia. 



Rusts of Shrubs: The rusts of the genus Phragmidium 

 attack the wild roses freely and may attack the cultivated 



PRO<'. & TRANS. N. S. Is ST. Scr., VOL. Xlf. TRANS. 23. 



