THE GENERAL CHARACTERS OF SEEDS 493 



Indian Plantain (Cacalia tuber osa Nutt). 



Achenes oblong, straight, or slightly curved, one-fifth in. in 

 length; brown; prominently ribbed, the ribs minutely roughened; 

 the apex of the seed with a slightly projecting rim or border to 

 which the pappus is attached ; the base with a circular ring ; pappus 

 with numerous fine, white, capillary bristles. 



Fig. 370A Fig. 370B 



Fig. 370. Seeds of Indian Plantain and Groundsel. A. Indian Plantain (Cacalia 



tuberosa). B. Groundsel (Senecio vulgaris). 



(Drawings by Charlotte M. King.) 



Groundsel (Senecio vulgaris L.). 



Achenes teretish or those of marginal flowers compressed, narrow, 

 cylindrical; 5 or 10-ribbed, pubescent; one-half in. long; upper 

 part expanded, extending beyond narrow portion of upper part of 

 achene ; lower portion with a depression ; color reddish ; pappus of 

 fine, white, capillary bristles. 



Burdock (Arctium lappa L.). 



Achenes 3-5-ridged, upper portion truncate, one-fifth to one- 

 fourth in. long, compressed or oblong, nearly straight to slightly 

 curved, 3-angled; surface mottled in appearance, due to the small 

 serrulate scales with projecting tips of ridges beyond the border; 

 scar surrounded by a circular lighter colored area ; scar at base 

 lighter in color; pappus of numerous short scales. In commercial 

 seeds, occasionally. 



