K 



244 FLOWERS OF FIELD, HILL, AND SWAMP 



the rainbow in the realm of the gods." Dr. Gray says the generic 

 name Ambrosia " is ill-chosen for these worthless and coarse 

 weeds." 



Mr. Burroughs says : " Ambrosia, ' food for the gods ' ! It must 

 be food for the gods, if anything, for, as far as I have observed, 

 nothing terrestrial eats it, not even a billy-goat." 



35. Spiny Cocklebur 



Xdnihium spinosum. — Family, Composite. Color, green- 

 ish yellow. Leaves, coarse, toothed or lobed, alternate. Stems, 

 stout, branching. 



Sterile and fertile flowers in different heads. Corolla at- 

 tending the single pistil, long, thread-like. 



An imported weed, too well known. There are spines at the 

 base of the leaves, slender, and of a yellow color, 3-parted. In 

 waste places, moist soil. Fruit, i inch long, pointed, beaked, a 

 rough bur clothed with hooked prickles, 2-celled. 



36 



X. strumdrium grows in barn-yards, having more slender 

 spines. 



37 



X. Canadcnse has stout and prickly fruit, the prickles hooked 

 backward. 



38. Purple Cone-flower 



Ruclb6ckia h/rta. — Family, Composite. Color, yellow, with 

 chocolate-brown, cone-shaped disk. Leaves, almost entire, 

 rough, hairy, as is the stem. Time, summer. 



Rays and disk-flowers present. 



This pretty weed has been brought to the East in clover-seeds 

 from Western fields. It grows i to 2 feet high, and colors whole 

 fields with a bright yellow, possessing strong roots, which are as 

 difficult to eradicate as those of the white daisy. New Jersey 



