THE GENERAL CHARACTERS OF SEEDS 



469 



Blue Vervain (Verbena* hastata L.). 



Nutlets 3-sided, with a distinct line of separation, back convex, 

 rugose, inner face 2-sided ; one-fifteenth to one-thirteenth in. long ; 

 color light brown; scar slightly elevated, whitish, at base of nut- 

 let. Often found in seed of clover. 



Hoary Vervain (Verbena strict a Vent.). 



Nutlets cylindrical, 3-sided, one-eighth in. in length, outer face 

 convex, back with 4 prominent veins, upper portion slightly pitted ; 

 color dark brown; whitish scar at base. Seed found in clover. 



Figure 336B 



% 



c 



Fig. 336. A. Hoary Vervain (Verbena stricta). B. White Vervain (Verbena 



urticaefolia) . 

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



White Vervain (Verbena urticaefolia L.). . 



Nutlets cylindrical, convex on back, 2-faced on inner side, with 

 prominent central line ; one-tenth to one-eighth in. in length ; back 

 somewhat rugose, with 2 or 3 prominent lines extending from base 

 to apex and some cross lines ; inner face somewhat granular ; scar 

 a whitish elevated point. Found in seeds of clovers. 



LABIATAE, MINT FAMILY. 

 Catnip (Nepeta cataria L.). 



Oval, dark brown seeds, about 1.5 mm. in length, slightly flat- 

 tened, surface smooth; one face bears a broad central, longitudinal 

 ridge, the base of which is marked by two white characteristic 

 spots, which are a part of the scar. 



American Germander (Teucrium canadense L.). 



Nutlets obovoid, one-tenth in. in length, outer surface convex; 

 color brown ; surface prominently rugose, reticulated except the scar 

 at the lower end. Common in commercial seed. 



