INTRODUCTION. xv 



odicals ; (2) in this catalogue there could not very well be given a 

 fuller synonymy with citations of places of publication, nor fuller 

 discussions, which are always desirable and often necessary for 

 clearness sake; (3) if the diagnoses of new species had been inter- 

 polated here and there, the uniformity of the catalogue would have 

 suffered. 



As it is, the Flora is the result of much labor and stands as a brief 

 index of the present knowledge of the flora of the state. In its 

 present form, the author hopes that it will be valuable for the pur- 

 pose for which it was prepared, viz., as a record of the higher vegeta- 

 tion of the state of Colorado as far as known to-day and as a guide 

 and help to those interested in its flora. Whatever shortcomings 

 there may be, the author hopes will be forgiven. The technical sys- 

 tematist will undoubtedly find many facts omitted which he would 

 expect to find in a " Flora of Colorado." 



From the summary given after the catalogue it can be seen that 

 the higher vegetation (fern worts and flowering plants) of Colorado 

 comprises over 700 genera and 2,900 species, a number sur- 

 passed only by California and perhaps by Florida out of all states 

 in the Union. The largest families are Carduacecc or the Composites 

 proper, with 568 species or about igy2% of the flora; Poacece or 

 grasses, 267 species or 9% ; Fabacece or Pea Family, 185 or 63^% ; 

 BrassicaccE 144, Rhinanthacece 106, Cyperacece loi, Polygonacece 94, 

 Ranitnculacecc 92, and Rosacea: 89 species, or between 3% and 4%, 

 etc. Just as remarkable as the large number of species of Compo- 

 sites (about y^ of the whole flora), is the small number of Pterido- 

 phytes. The ferns proper are only 25, to which are to be added 15 

 other fernworts. The same may be said of the Gymnosperms, only 

 20 in number. 



The author has had the help of several specialists in certain groups. 

 Professor L. AI. Underwood has prepared the manuscript of the 

 Pteridophyta, and ]\Ir. H. D. House that of the family Violacecc. 

 Mr. G. V. Nash has given valuable assistance in the grasses. 

 The account of the Polygonacece was written in conjunction with 

 Dr. J. K. Small. Dr. Theodor Holm has characterized the groups 

 and species of Carex and listed the specimens of that genus, while 

 the author prepared the key to the groups. Mr. S. H. Burnham, 

 Mr. H. D. House and Mr. W. W. Eggleston have assisted in listing 

 the localities and Mrs. William Mitchell in copying the keys. 



P. A. Rydberg. 



New York Botanical Garden, 

 New York, March, 1906. 



