68 (67) Leaves grass-green or gray-green, 

 pinnate to tripinnately lobed, both 

 opposite and alternate, foliage re- 

 sembling that of Artemisia steller- 

 riana (Fig. 67) , but lacks the wooly 

 hairs; flowers in greenish terminal 

 clusters; upper beaches and waste 



places Ambrosia artemisiifolia, 



Ragweed 



Figure 72. 



69 (61) Leaves broad triangular to oval. 

 69 (61) Leaves linear or lanceolate 



70 

 73 



70 (69) Large vinelike plants with thorns; usually 

 creeping over other vegetation, may form im- 

 penetrable thickets; leaves ovate or oval with 

 three prominent main veins, tendrils at the base 

 of some leaves; flowers in loose umbels; berries 



blue ; plants of old dunes and sea cliflFs 



Smilax rotundifolia, 



Common Greenbriar (other species may be 



found) 



Figure 73. — Stem and leaf X%- 



70 (69) Not vinelike, no thorns. 



71 



71 (70) Plants with light green, ovate-deltoid, 

 serrate dentate or serrate leaves, very 

 mealy especially below; flowers green- 

 ish in paniculate spikes; long tap roots; 

 on beaches but a common weed of 



waste places Chenopodium album, 



Lamb's Quarters 



Figure 74 



-Leaf Xl%. 



71 (70) Plants with darker green leaves, no mealy spots on leaves; flowers variable 72 



31 



