MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 15 
Dalibarda with Rusran, through Chamaerhodos and Alchemilla, with SANGUISORBEAE, 
etc. The relation of the tribes of ROSACEAE may be represented in the following 
diagram : 
SAXIFRAGACEAE. 
POMACEAE. DRUPACEAE. 
SPIRAEEAE. 
CERCOCARPEAE. RosEAk. 
DRYADEAE. RUBEAE. SANGUISORBEAE. 
( Waldsteinaa.) (Dalibarda.) (Alchemilla.) 
POTENTILLEAE. 
RANUNCULACEAE. 
LIMITATION OF GENERA. 
As stated before, Comarum, Sibbaldia, Horkelia and Ivesia have been included in 
Potentilla by Bentham and Hooker, Baillon, Greene and others. The only logical course 
to be taken would have been to include also Duchesnea and Fragaria. The latter differs 
