PR H FACE, 



There is iiuich confusion in the names applied to our North Ameri- 

 can jrnisses. This is partly due to llie fact that much new material 

 has been collected since the revision of some of the imiiortant genei-a. 

 The practice, formerly more prevalent than at present, of erecting' 

 new species on the basis of a single specimen or of a very few speci- 

 mens at most, has added to this confusion. The economic importance 

 which the grasses have assumed in the last two decades 1ms made this 

 confusion all the more embarrassing. It therefoi'e seems desirable 

 that the bibliography, synonymy, and systematic relationships of 

 American grasses be woi'ked out as rapidly as possible. The pi'csent 

 paper by Professor Hitchcock is an attempt to do this for the genus 

 Leptocldoa. It is based chiefly upon the material in the herljai'ium of 

 the U. S. National Museum and that of the U. 8. Department of Agri- 

 culture, but all the important public herbaria in this country were 

 consulted during its preparation. The descriptions of the species are 

 diagnostic rather than complete, but it is hoped that these will serve 

 the purpose of students of systematic botany. Much time has been 

 spent in working out the pi'oper relationship of the species and it is 

 hoped that the short descriptions, the text figures illustrating the 

 spikelets of each species, the plates taken from herbarium si)ecimens 

 of several species, and the key to oui- United States si)ecies will take 

 the place of more complete descriptions and render this papei- \'alua- 

 ble to students of this genus. 



The species of Lepiochloa are iidiabitants of the warmer regions, 

 only one or two of our species extending as far nortli as New York 

 and Illinois. One of the si^ecies, Lepiochloa duhia, called sprangle, is 

 an imijortant range grass in the Southwest, and recent experiments 

 indicate that it will prove a desirable grass for cultivating in semiarid 

 regions. 



W. J. Spillman, 



Agrosiolofjist. 

 Office of the Agrostologist, 



Washington, D. C, October U, 1902. 



5 



