i65 



ized by the medium sized, somewhat slender pod, and frequently 

 with a rather small pale green seed ; and the field class, characterized 

 by their vigor and productiveness. Four distinct types are recog- 

 nized among field beans. The following key to the group has been 

 prepared by John W. Gilmore,^ Assistant Professor of Agronomy 

 at Cornell University: 



Seed 1 . 5 cm. or more in length, more or less reniform, ratio — 

 length, width, thickness-1-.4869-.3731 Kidney. 



Seed between i and 1.5 cm. in length. Thickness exceeding half 

 the length. 1-.6537-.6029 Marrozv. 



Seed I to 1.2 cm. in length. Thickness less than half the length. 

 i-.678-.4975 Aledium. 



Seed .8 cm. or less in length, not reniform. i-. 7467-. 6096. .Pea. 



On the following pages the varieties of the various species are 

 for convenience grouped into two main classes — dzvarf and climb- 

 ing. These classes are subdivided into green-podded and wax- 

 podded varieties. The individual varieties of the various sub- 

 classes are treated in alphabetical order. 



Key to Economic of the Genus Phaseolus 

 (P. vulgaris, P. lunatus, P. niul tif 1 r us). 



Every author dealing with this genus, for the sake of bringing 

 order out of chaos, has felt obliged to formulate a table for the 

 determination of varieties. Martens used characters based entirely 

 upon the form and color of seed. This work fails to serve our 

 purpose, inasmuch as it treats chiefly of European forms. Wing 

 followed Martens to a great extent, and evidently with a view of 

 simplifying matters introduced edible-pod characters. Irish went 

 still further and introduced plant characters. While this is very 

 interesting from a botanical standpoint, it is of little use to the 

 seedsman or grower, for the reason that all of these characters are 

 not visible at the same time ; that is, when the edible pods are 

 present the dry seed is not, and when we have the dry seed the 

 plant and edible-pod characters are not accessible. 



After careful inquiry from several seedsmen and growers as to 

 the practical value of a key based entirely upon seed characters, 

 the preparation of the following table was undertaken. In view of 

 the looseness of color nomenclature, of the variability in seed of 



'A Botanical Study of Field Beans, A Thesis, p. 5 (1905). 



