38 THE SEEDS OF THE BLUEGRASSES. 
the apex; surface sometimes slightly grooved or ridged lengthwise, otherwise smooth; 
color varying from light 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 
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 
Fic. 34.—Seeds of sedge (Carex cephalophora): a, seeds th : . 
gee are e species most commonly found in 
inclosed by the perigynium; b and c, seeds with 2 
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 »,, 85.—Ergot (Clave 
beyond the glume and palea, attains about twice the length of — ceps purpurea) of Ken- 
the glume, and is club-shaped, straight, or, more commonly, — tucky bluegrass: a,en- 
somewhat curved. It is black, dull, and somewhat grooved /#78¢4; >, natural size. 
lengthwise. (Fig. 35.) 
O 
