PREFACE. 



To a person walking in the country in search of rest from labor 

 the wild plants are very friendly if he has a speaking acquaintance 

 with them. Such an acquaintance is of untold value as a means of 

 rest and recreation. Yet to most persons our books on botany, 

 instead of opening the path to knowledge, close it with the barrier 

 of teclmical language. Botanical science is beginning to recognize 

 the prohibitive effect of this barrier and to take steps to open the 

 path to the public. The Flora of the District of Columbia and 

 Vicinity now presented for publication is provided with keys to the 

 famihes, genera, and species, and in the preparation of these' keys 

 common words have been used extensively as substitutes for tech- 

 nical and unusual words. This is especially true of the key to the 

 families, which is so written that a person with almost no knowledge 

 of botany can trace a strange plant to its proper family. The 

 identification of many of the native species is made still easier by 

 the illustrations, and it is only the limitation of space and cost 

 that has prevented the more extensive use of these photographic 

 reproductions. 



Frederick V. Coville, 

 Curator of the United States National Herbarium. 



