T O 



SIR WILLIAM JACKSON HOOKER, K. H., LL. D„ 



REGIUS PROFESSOR f»F BOTAKY IN THE U>-IVERSITV OF GLASGOW, F.TC, F.TC, 

 WHOSE NAME IS IDENTIFIED WITH 



NORTH A3IERICAN BOTANY, 



THIS WORK, 



WHICH IS GREATLY INDEBTED TO HIS GENEROUS ENCOURAGEMENT, 



IS MOST RESPECTFULLY DEDICAT'eD 



BY HIS OBLIOED FRIENDS, 



THE AUTHORS. 



