Panisifir FiitKji of Illinois. 155 



Roman numerals often following the above indicate the stage 

 of development of the fungus: viz. 1., cecidium; II., uredo: 

 III., teleutospore. 



Key to the (tenera of Uredine.e. 



I. Spores at maturity forming a more or less powdery mass. 



A. Spores with a permanent pedicel, mostly smooth and 



dark brown. 



1. Spores one-celled Uromyces. 



2. Spores two-celled, septum horizontal. . .Puccini a. 



3. Spores three-celled, septa in different planes. 



Triphragmium. 



4. Spores three or more celled, septa horizontal. 



Phragmidium. 



5. Spores many-celled, septa variously placed. 



Ravenelia. 



B. Spores with deciduous pedicels or none, one-celled, 



mostly roughened with minute projections, usually 

 yellow or reddish-brown. 



1. Sorus with a peridium, spores produced in vertical 



chains, without pedicels. 



a. Peridium cup-shaped, rim-border mostly toothed 



or lobed and recurved iEciDiUM. 



b. Peridium hemispherical or l)owl shaped, deei)ly 



immersed Endophyllum. 



c. Peridium elongated, usually cylindrical or coni- 



cal, soon split-fringed above Roistelia. 



d. Peridium various, bursting irregularly, white, 



on Coniferai Peridermium. 



2. Sorus without peridium. 



a. Spores produced in vertical chains, without ped- 



icels, usually accompanied with spermogonia. 



C.^OMA. 



b. Spores produced on pedicels (deciduous), not 



accompanied with spermogonia Uredo. 



II. Spores at maturity embedded in gelatine, two-celled, sep- 



tum horizontal, pedicel long Gymnosporangium. 



