38 



THE SEEDS OF THE BLUEGRASSES. 



the apex: surface sometimes slightly grooved or ridged lengthwise, otherwise smooth; 

 color varying from hght brown to greenish or dark brown. (Fig. 34.) 



Seeds of sedge (Carex) are found in 

 both American and European bluegrass 

 seed. Owing to the wide area of their 

 I production, the seeds of various species 

 of Carex occur in commercial blue- 

 grass seed. The seeds of Carex are 

 fruits (akenes) and occur free or in- 

 closed within a sac-like covering (the 

 perigynium). Carex cephalophora is 

 FIG. 34.-Seeds of sedge ( Carex c^pftaZoMom): a, seeds ^^^ .^^ ^^^^ commonly found in 



inclosed by the perigynium; h and c, .seeds with f i ki A 



perigynium removed; d, natural size of seeds. Kentucky bluegrass seed. 



ERGOT OCCASIONALLY FOUND IN COMMERCIAL 

 BLUEGRASS SEED. 



Claviceps purpurea (Fr. ) Tul. 



ERGOT. 



This is a fungus growth affecting the grain (caryopsis) of 

 many grasses. It is very common in the seed of redtop and 

 other species of Agrostis, and occasionally occurs in bluegrass 

 seed. The grain of the seed becomes elongated, extending 

 beyond the glume and palea, attains about twice the length of 

 the glume, and is club-shaped, straight, or, more commonly, 

 somewhat curved. It is black, dull, and somewhat grooved 

 lengthwise. (Fig. 35.) " 



a 



Fig. 35.— Ergot (Clavi- 

 ceps purpurea) of Ken- 

 tucky bluegrass: a, en- 

 larged; 6, natural size. 



i 



o 



