IV PREFA CE. 



The arrangement of orders and families adopted is essentially that 

 of Engler & Prantl's " Natiirlichen Pflanzenfamilien," Berlin, 1890- 

 1901, an arrangement which seeks to bring out something of the de- 

 velopmental relationships of the groups by proceeding from the more 

 simple to the more complex. Order and family are not here regarded 

 as synonymous terms, but are used, as by zoologists, in the sense of the 

 former being composed of the latter ; thus the order Liliales is com- 

 posed in our territory of the families Juncaceae, Melanthaceae, Lilia- 

 ceae, Convallariaceae, Smilaceae, Haemodoraceae, Amaryllidaceae, 

 Dioscoreaceae, and Iridaceae. 



In the scientific nomenclature the principles adopted by the botan- 

 ists of the American Association for the Advancement of Science at 

 a meeting held in Rochester, N. Y., in 1892, and in Madison, Wis. , 

 in 1893, supplementary to the Code of Nomenclature adopted by the 

 International Congress of Botanists held in Paris, France, in 1867, 

 have been followed ; these principles are essentially the same as those 

 followed by American zoologists. An English name has also been 

 associated with each species, accepted either from popular usage 

 or chosen in reference to some more or less distinctive feature of the 

 plant. The citation of synonyms is mainly restricted to cases in 

 which the names here used differ from those in " Illustrated Flora." 



Keys formed by the grouping of contrasting features have been 

 prefixed to the descriptions of species, genera and families, and a 

 general key to the orders follows this preface. 



The collections on which the descriptions are based are nearly all 

 at the New York Botanical Garden. 



I take much pleasure in acknowledging important assistance in the 

 preparation of the work by my associates, Prof. L. M. Underwood, 

 Dr. John K. Small, Dr. P. A. Rydberg, Mr. G. V. Nash, and Mr. 

 E. P. Bicknell. 



N. L. B. 



NEW YORK BOTANICAL GARDEN, 

 August 24, 1901. 



