124 EEPORT OF THE No. 3 



Black Spruce (Picea mariana (Mill.) BSP.) 



Arceuthohium pusillum Peck. The dwarf mistletoe is not uncommon on black 



spruce throughout Ontario. In some cases entire swamps are badly 



diseased, the trees loaded with witches' brooms, due to the stimulation 



of this parasite. 

 Armillaria mellea Quel. Frequent on the roots. It is also reported here 



for the first time as the cause of a heart rot. 

 CoUricia tomentosa (Fr.) Murr. Occasional on roots. 

 Fomes roseus (A. & S.) Cooke. Occasional on dead wood;" whether or not tlio 



cause of a heart rot remains undetermined. 

 Fomes ungulatus (Schaeff.) Sacc. Very abundant on dead wood. It has 



also been found causing heart rot. 

 Melampsoropsis ahietina (A. & S.) Arth. This leaf rust and the following 



one are abundant, in some cases causing considerable defoliation.' Tliey 



are reported here on both hosts, namely, black spruce, and Labrador tea 



(Ledum groenlandicum). 

 Melampsoropsis cassandrae (Peck & Clint.) Arth. This rust, as in the case 



of the last, is reported here as wintering over in the alternate host. 



Found on both hosts in the Timagami Forest Eeserve, namely, black 



spruce, and cassandra (Chamaedaphne calyculata). 

 Phaeolus sistotremoides (A. & S.) Murr. Common, and like the following, 



the cause of a destructive heart rot. 

 Porodaedalea pini (Thore) Murr. 

 Tyromyces anceps (Pk.) Murr. This fungus has been regarded as very rare 



in eastern America, but in our northern country it is found to be the 



frequent cause of decay in the fallen trunks of various conifers. 



Banksian or Jack Pine (Pinus banksiana Lamb.) 



Cronartium cerebrum (Pk.) Hedg. & Long. This stem rust occurs abund- 

 antly and often destructively on the jack pine. It is also found abund- 

 antly on the leaves of the red oak in the Timagami Forest Eeserve, on 

 which, however, it causes no appreciable injury. 



Cronartium comptoniae Arth. This interesting stem rust of the jack pine 

 was found on both of the alternate hosts, the sweet fern (Myrica aspleni- 

 folia) and sweet Gale (Myrica Gale). It is quite certain that it will be 

 found on its coniferous hosts in the Timagami Forest Eeserve, the 

 locality referred to in this note. 



Cronartium pyriforme (Pk.) Hedg. & Long. Found on its alternate host, 

 the bastard toad-flax (Comandra umbellata), south of Parry Sound. 

 It is to be expected that this stem rust will be found on the jack pine 

 in Northern Ontario. 



Lophodermium pinastri (Schw.) Chev. Frequent and causing more or less 

 extensive leaf fall. 



Phaeolus sistotremoides. This together with the following are the commonest 

 cause of heart rot in this pine. 



Porodaedalea pini. 



Eed Pine (Pinus resinosa Ait.) 



Cronartium cerebrum (Peck) Hedg. & Long. A rare rust on red pine in the 

 Timagami Forest Reserve. 



