The Production of New and Improved Varieties of Timothy 349 



practical purposes and they can probably be disregarded in choosing 

 plants in selection work. 



Head characters. — In timothy, as in wheat and oats, 

 wide variation is found in the head characters. The 

 most noticeable of these are the variations in length 

 and in thickness, but the heads also vary in form of 

 apex and of base. The following are the main 

 characters that show variation, and in each of the 

 characters several grades of intermediates may occur: 

 The heads may be long or short 

 (Fig. 87), thick or thin (Fig. 88), 

 dense or lax, greenish or purplish 

 in color before mature, gray or 

 tawny in color when ripe, simple 

 or branched (panicled or barbed), 

 erect or nodding, and continuous 

 or interrupted. The apex and base 

 of the head may be either blunt or 

 pointed (Figs. 89 and 90). A blunt 

 apex and base give a cylindrical 

 head; a pointed apex and base 

 give a fusiform head; a blunt Fig. 87. — Variation in length of head 



base and pointed apex give a conical head; a pointed base and 



blunt apex give a clavate or club- 

 shaped head. 



All these shape characters of 

 the head are presented in many 

 degrees, so that the shape and 

 size of head show an almost infinite 

 number of forms. Of rather special 

 interest are the panicled head and 

 the interrupted head. The panicled 

 head (Plate V, Fig. 3) is not 

 uncommon and has been bred into a 

 pure race. In this form, which has 

 also been called barbed, or branched, 

 the rachis, or main axis of the head, 

 is distinctly branched. In the inter- 

 rupted head a space of greater or 



,,...,., , , less extent in the middle portion of 



Fig. 88. — Vartatton tn thickness of head ,, , . . , . .,. 



the rachis remains bare, failing to 



develop spikelets. This peculiar character, which would seem to 



