CONTRIBUTIONS FROM THE HERBARIUM OF 

 COLUMBIA COLLEGE -No. ii. 



Preliminary Note on tlie North Amer- 

 ican Species of the Genus 

 Tissa, Adans. 



By N. l. britton. 



(Repi'ij)tefl from the Bulletin of the Torrey Botanical Club, Vol. XVI, No. 5, May, 1889.") 



