34 (31) Leaves not in a rosette; variable shaped leaves on erect stems. 



35 



35 (54) Leaves not entire 



35 (3^) Leaves entire, not toothed or lobed. 



36 



38 



36 (35) Leaves covered with stiff 

 bristles, older leaves cordate, 

 slightly lobed with undulate 

 margins; fruit an olive-shaped 

 bur with recurved spines, 

 plants of beach and dunes. . . . 



Xanthium echinatum, 



Cocklebur 



Figure 38.— Leaf XL 



36 (35) Leaves smooth with no bristles, ovate lanceolate to obovate; pale green plants, 

 no burlike fruits 



37 



37 (36) Leaves serrate, ovate-lanceolate to 

 ovate or obovate, glabrous or sparingly 

 pubescent below; flat topped clusters 

 of many pink or purple flowers; plants 



of the tidal marsh Phichea purpurascens 



var. succulenta, Salt Marsh Fleabane 



Figure 39.— Leaf XL 



37 (36) Leaves obovate or oblanceolate, 

 sinuate toothed, narrowed to base, 

 young leaves taste of horseradish; 

 fruit a cone-shaped silique; plants 



of the beaches Cakile edentula, 



Sea Rocket 



Figure 40. — Leaves XI- 



19 



