THE GENERAL. CHARACTERS OF SEEDS 



497 



Fig. 375A 



Fig. 375B 



Fig. 3750 '■ 



Fig. 375, Seeds of Corn-flower and Knapweed. A. Bamaby's Thistle or 

 Knapweed (.Centaurea solstitialis) ; a, achene with pappus, c, pappus re- 

 moved, b and d, achenes, natural size. 

 B. Corn-flower (.Centaurea cyanus). C. Achenial hairs of Corn-flower. 



(A, after Hillman, Bull. Nev. Agr. Exp. Sta. ; B, after Nobbe; C, drawing by 



S. B. Fraoker.) 



Bristly Ox-tongue (Picris ■ echioides L.). 



Aehene elliptical, narrowed at base, with projection at tip ; one- 

 tenth in. in length ; light brownish red ; wrinkled transversely, espe- 

 cially toward apical end. Found in seed of alfalfa and clover. 



Oyster Plant, Salsify {Tragopogon porrif alius L.). 



Achenes linear, terete, beaked or long, covered with scalelike 

 tubercles, on the ribs, or igerely roughened, light straw-colored or 

 darker pappus of numerous plumose bristles ; smialL scar at apex, 

 whitish with a depression sear at base with an oval depression. 

 Reported as a "weed of alfalfa meadows." 



Meadow Salsify {Tragopogon pratensis L.) . 



Achenes linear, terete, one-half in. or little more long, exclusive 

 of beak ; scar at base, whitish, with an oval depression ; beak one- 

 third in. long; scar at end of beak whitish, with a depression, 

 striate, smooth or slightly roughened, light straw-colored or darker ; 

 pappus of numerous soft, brownish, plumose bristles. 

 32 



