728 REPORT OF NEW JERSEY STATE MUSEUM. 



d. Involucral bracts with hooked bristles, a large course branch- 

 ing plant with purplish flower heads. [Arctium minusy 

 dd. No hooked bristles to the involucral bracts. 



e. Foliage very bristly. Carduus, p. 778 



ee. Foliage not bristly. 



/. Leaves verticillate, flowers pink. 



g. Leaves linear, plant 3-6 dm. high, flower head single, 



10 mm. wide. Sclerolcpis, p. 731 



gg. Leaves ovate lanceolate, plant .5-3 m. high, flower 



heads very numerous in a terminal cymous panicle. 



Bupatorium, p. 732 

 //. Leaves not verticillate. 



g. Flower heads red-purple in a terminal cymcse, 

 panicle. Plant 9-27 dm. high, not aromatic. 



Vernonia, p. 730 

 gg. Flower heads pink, broad in a terminal corymbose 

 cyme. Plant 4-9 dm. high, aromatic. 

 h. Leaves sessile cordate or clasping at base. 



Pluchea foetida, p. 765 

 hh. Leaves petioled. P. camphorata, p. 765 



ggg. Flower heads red-purple in a long, usually dense, 

 terminal spike or spike-like raceme, leaves linear 

 or linear lanceolate. Plant 3-20 dm. high. 

 h. Bracts of the cyhndrical involucre oblong or 

 oval obtuse, achenes pubescent or smoothish. 

 Lacinaria spicata, p. 740 

 hh. Bracts of the obovoid involucre oblong, obtuse 

 or pointed, achenes hairy. 



L. graminifolia pilosa, p. 740 

 gggg- Flower heads blue. Bupatorium, p. 732 



ggggg. Flower heads purplish, leaves whitish wooly. 



Gnaphalium purpureum, p. 768 

 aa. Ray flowers present around the central disc. 

 b. Rays yellow. 



c. Notched at the end. Helenium, p. 774 



cc. Rays not notched. 

 d. No pappus. 



e. Achenes with barbed awns. Bidens, p. 772 



ee. Achenes without awns. 

 /. Plant rough. 



g. Leaves 2-7 pointed or lobed. 



Rubeckia laciniata, p. 769 

 gg. Leaves not lobed. 



h. Disc greenish or yellowish. Hclianthus, p. 769 

 hh. Disc brown. 



i. Flower less than 100 mm. broad, 

 y. Leaves linear sessile. 



Helianthus angustifolius, p. 769 

 jj. Leaves lanceolate. [Rubeckia hirta]" 



^ Burdock, a weed in waste ground. 



" Black-eyed Susan, a common weed in fields. 



