GRASSES OP IOWA. 



91 



The minimum degree of temperature for corn is 49.9 F., 

 maximum 134.8 F., optimum 91.4 F. To this table may be 

 appended the results obtained for a few cereals in our labora- 

 tory, greenhouse (were germinated in sand) and field. The 

 temperature of the laboratory was not kept. The seeds of the 

 laboratory were germinated in porous clay trays.* 



LABORATORY AND GREENHOUSE TEST. 



According to Sempolowski, the percentage of germination 

 in grasses is as follows: 



Agrostis stolonifera . . . 



Agrostis alba 



Aira caespitosa 



Aira flexuosa 



Alopecurus pratensis 



Anthoxanthum odoratum. . . 

 Arrhenatherum avenaceum. 

 Arrhenatherum flavescens. . 



Bromus mollis 



Cynosurus cristatus 



Dactylus glomerata 



Festuca ovina 



Festuca pratensis 



Festuca rubra 



Holcus lanatus 



Lolium italicum , 



Lolium perenne 



Phalaris arundinacea 



Phleum pratense 



Poa pratensis , 



Poa memoralis 



Poa trivialis 



28 

 19 

 6 

 5 

 5 

 23 

 44 

 14 

 72 

 23 

 58 

 48 

 54 

 39 

 27 

 62 

 75 

 10 

 90 



3 



*A fuUer account of these studies is given by Pammel. Proc. Soc. Prom. Agrl. 

 Scl. 1898: 194. Oontr. Bot. Dept. Iowa St. Coll. Agrl. and Mechanic Arts. 12. 



