LICHENS ()]•• IOWA. 85 



O. PUiA'iNATA Rchm. Oil /Hiidorarpuii iiiiii/dliDii. I'\iyette. 

 This plant has not been collected before in America so far 

 as I can ascertain. The spores are 15 to 18/^ long and 5 

 to 6/1 wide, thus being a little wider than those of the Euro- 

 pean plant. 



GRAPH IS Ac/i., Xyl. 



G. scRirTA (Z.) Ach. Trees. Fayette, Clayton, Bremer. 



Johnson, Linn, Shelby, Winneshiek, Story and Floyd. 



xA variety of forms was collected as to length, color and 

 form of apothecia, and color and amount of thallus. One 

 form with spores from four- to eight-celled seems to be near 

 O. dendritica, which has been reported from Illinois and 

 Minnesota. 



G. SCRIPTA (Z.) Ach.. var. serpentina Ac]i. Trees. 

 Fayette, Shelby, Winneshiek. 



G. eulectra Tuck. Trees. Fayette, Clayton. 



Fam. ARTHONIEI. 



ARTHONIA Ach..XyI. 



A. i>ecideelea Aj'/. Trees. Fa^-ette. Bremer. Clayton, 

 Story. Linn. Johnson. 



A. DisPERSA i^Schrad.) Xyl. Trees. Fayette. 



A. RADiATA [Pcrs.] Th. Fr. Trees. Fayette, Bremer, 

 Clayton, Story, Floyd. Linn, Johnson. 



A. PUNCTiFORMis Ach. Trecs. Fayette. Bremer. 



A. sPECTABiEis Flat. Trees. Fayette. Bremer. Clayton, 

 Story, Linn. 



A, POI.VMORPIIA Ach. Trees. Fayette. Usually considered 

 to be a tropical hchen, but ours agrees with specimens in 

 the Tuckerman herbarium. 



