141 
488. Zinnqi multiflora L.. On the Mississippi, Pursh. 
489. Boebera chrysanthemoides Wild—Tagetes pap- 
posa Mich. On the overflowed banks of the 
Mississippi, Mich, and Pursh. 
490. Helenium canaliculatum Lam. In Louisiana. 
491. Mesodetra alata Raf.—Rudbeckia alata Jaq.—Hc- 
lenium quadridentatum Wild. Pursh. On the 
banks of the Mississippi, Pursh. It must form a 
new genus, which differs by the perianthe, sta¬ 
mina and flowers from Rudbeckia and Helenium . 
Stamina 4. 
492. Silphium laciniatum L. On the Mississippi, 
Pursh. 
493. Silphium terebinthaceum L. On the Mississippi, 
Pursh. Mich. 
494. Scorzonera pinnatifida Mich. On the Missis- 
sippi, Mg. 
vvvw 
CLASS IV.—SYMPHOGYNIA. 
Stem or caudex vascular and fibrous, vessels and 
fibres in concentrical layers, surrounding a central 
pith or hollow. 
Flowers with a single ovary, connected with the 
calyx or the perigone ; stamina never inserted on a 
peripetal corolla, or interior peripetal perigone. 
Bodies 'with a root and caudex , commonly a stem , 
sometimes a woody one , often branched , always with 
leaves or scales , and conspicuous flowers , fruits and 
