PREFACE. 
In identifying recent Panama material of Inga, a very large 
American genus of leguminous trees, Mr. Henry Pittier, of the 
Bureau of Plant Industry, United States Department of Agricul- 
ture, has found it necessary to undertake a critical review of all the 
species of the genus. No general treatment of Inga has appeared 
since Bentham’s extensive monograph in 1875, although many 
species have been described since that year. For several reasons a 
conclusive revision of the genus is impracticable at the present time. 
Many of Mr. Pittier’s conclusions, however, are embodied in the 
accompanying paper, which consists chiefly of critical observations 
upon the characters and status of some of the older species, notes on 
their arrangement in a natural classification, and descriptions of new 
species as represented by specimens in several of the larger American 
herbaria. There is given, in conclusion, a list of all the species 
deemed valid, with an indication of those lacking in the American 
herbaria consulted. 
FrepertcK V. CoviLie, 
Curator of the United States National Herbarium. 
Ill 
