SOME GRASSES OF THE NORTHEAST &7^ 



KEY TO THEIR IDENTIFICATION BY VEGETATIVE CHARACTERS /^^ 



by 

 C. E. PHILLIPS 1 



In the last few years an increasing interest in weed-free turf and the wide acceptance of chem- 

 ical herbicides has sharply focused attention on the necessity of identifying grasses by their vege- 

 tative characters. A European worker is credited with doing the basic work on the use of vegetative 

 characters in an identification key about 80 years ago. Carrier (3) in 1917 developed the first in 

 North America. Since then a number of such keys have been developed by various workers in the 

 United States and Canada (see bibliography). None of these keys, however, included anywhere 

 near all the grasses of economic importance in the Northeastern states. 



The key presented here is an outgrowth of 15 years of teaching students to identify pasture 

 grasses and some common weed grasses in their vegetative (non-flowering) state. Using descriptions 

 of grasses from several publications, a number of tentative keys were constructed and tried with 

 unsatisfactory results. Many of the grasses were found to show great variation from region to region 

 in the detailed description of their vegetative characters. It was apparent that if a key was to be 

 useful it would have to be based on vegetative descriptions made of the grasses growing in the region. 

 Approximately 800 vegetative descriptions were made and used in the development of the key. Most 

 of these were of grasses collected in the 12 Northeastern states and Virginia. In order to get a better 

 idea of variations, however, some collections were made in a total of 34 states and one Canadian 

 province. To assure uniformity, all descriptions were recorded on keysort punch cards printed with 

 a standard legend. Most of the key has been field checked by students and co-workers in Delaware 

 and adjoining states. 



No effort was made to include all the grasses of the Northeast in the key. An effort was made, 

 however, to include most of those having economic importance. Most of those included are either 

 species cultivated for various purposes or weed grasses of mostly agricultural situations. In addition 

 to these, a number of grasses of interest to conservationists and wildlife people were also added. 



Scientific names of the grasses are those given by Hitchcock (6) . Common names, in most cases. 

 are those used most frequently by many authorities. In a few cases the author found it necessary to 

 coin a common name that seemed appropriate. 



DISTINGUISHING THE GRASSES FROM THE GRASS-LIKE PLANTS 



There are a number of the grass-like plants that may be easily confused with the true grasses. 

 Not many of these are to be found in agricultural situations except in wet pastures and meadows. 

 One sedge, however, nutgrass (Cyperus esculentus), is a common weed in cultivated fields in the 

 Northeast, and the path rush (Juncus tenuis) is found in a variety of situations, particularly on com- 

 pacted soil. 



Since the key presented here deals only with the grasses, it is necessary to be able to distinguish 



Chairman, Department of Agronomy, University of Delaware. 



