THE GENERAL CHARACTERS OP SEEDS 



501 



\ 



B 



A 

 Fig. 380A Fig. 3S0B 



Fig. 380. Lettuce Seeds. A. Lactuca scariola; A, side view of an achene, en- 

 larged. B, a group of the same, natural size. C, an achene bearing its 

 beak and fragile pappus. 



B. Prickly Lettuce (Lactuca scariola var. integrata.) 



(A, after Hillman, Bull. Nev. Agr. Exp. Sta. ; B,. drawing by L. R. Collins.) 



toward the beak, somewhat flattened, on one side margined, faces 

 convex, with 5-7 longitudinal nerves; scar circular, with a small 

 depression. 



Rattlesnake Root (Prenanthes alba L.). 



Achene oblong or columnar, truncate, somewhat flattened, 4-5 

 angled, brownish ; upper part with a projecting ring to which the 

 bristles of pappus are attached ; scar at the base whitish, not prom- 

 inent ; one-eighth in. in length ; pappus tawny. 



Fig. 381A Fig. 381B 



Fig. 381. Seeds of Rattlesnake Weed and False Calais. A. Rattlesnake Weed 



(Prenanthes alba). B. False Calais (Agoseris cuspidata). 



(Drawings by Charlotte M. King.) 



