1963] 



LISTS AXD KEYS OF THE CEDAR RUSTS OF THE WORLD 



315 



7. Peridial cells subspinulose. 

 6. Peridial cells smooth. 

 4. Peridium strongly revolute. 



On Cydonia 



1. Aecia aecidioid. 

 Aecia roestelioid. 



trachysorum. 

 hyalin u m. 

 floriforme. 



libocedri. 



1. 



Peridium rupturing at apex and more or less along the sides. 

 3. Peridial cells verruculose with long papillae. asiaticum. 



3. Peridial cells tuberculate with blunt papillae. Icernianum. 

 Peridium losing tubular form, becoming lacerate and spreading. 



4. Peridial cells verrucose. 



5. Aeciospore-wall pale yellow, coarsely verrucose. clavipes. 



5. Aeciospore-wall cinnamon-brown, moderately verrucose. clavarii forme or gracile. 

 4. Peridial cells rugose, linear-rhomboid; aeciospores medium-sized (18-28 /x). 



6. Inner and side walls strongly rugose with ridges of varying length. confusum. 

 6. Inner and side walls rugose with long narrow ridges interspersed with round- 

 ish papillae. nidus-avis. 



4. Peridial cells rugose, rhomboid; aeciospores large (28-45 aO- tremelloides. 



peridium tubular, peridial cells verrucose, aeciospores 



21-24 X 



speciosum. 



On Fendlera 



Aecia roestelioid, 

 24-29 ll. 



On Gillenia 



Aecia roestelioid, peridium soon lacerate and spreading, peridial cells rugose, aecio- 

 spores 17-21 X 21-26 ll. exterum. 



On Heteromeles 



Aecia roestelioid, peridium not spreading much, peridial cells spinulose. exiguum. 

 On Juniperus 



Aecia roestelioid, on galls, peridium lacerate, aeciospores 16-19 X 19-29 ll. bermudianum. 

 On Macromeles (See Mains) 



On Malus 



1. Aecia aecidioid. 



2. Aeciospores small (18-20 x 14-23 ll). libocedri. 



2. Aeciospores large (23-27 X 27-39 ll) . nootkatense. 

 1. Aecia roestelioid. 



3. Peridium conical or subcylindrical, dehiscent only at apex 1-1.5 mm high. 



hemisphericum. 



3. Peridium cornute, retaining shape, 3-5 mm high. 

 3. Peridium tubular, spreading or more or less erect after rupturing. 



4. Peridial cells tuberculate. 



4. Peridial cells verrucose. 



5. Aeciospores 21-32 X 24-39 p, wall yellow. 



5. Aeciospores 18-24 diam., wall cinnamon-brown. 

 4. Peridial cells spinulose. 

 4. Peridial cells rugose. 



6. Aeciospores small (15-19 X 18-25^), wall thin (1-2 fi). 

 6. Aeciospores medium (18-23 X 23-38 /i), wall medium (1.5-2.5 ll) 

 6. Aeciospores large (28-35 X 30-45 ll), wall thick (3-5^). 



3. Peridium strongly revolute ofter dehiscence. 

 On Mespilus 



Aecia roestelioid, becoming lacerate, peridial cells rugose. 

 On Micromeles (See Sorbus) 



cornutum. 



yamadae. 



clavipes. 

 miyabei. 

 leve. 



globosum. 

 fenzelianum. 

 tremelloides. 

 juniperi-virginianae. 



confusum. 



