4 PREFACE. 



Agriculture. The task has been a laborious one, far more laborious 

 than the printed results suggest, but in the progress of the work its 

 necessity has been amply demonstrated. The result is a substantial 

 basis for the uniform designation of economic tropical plants in accord- 

 ance with the system now followed by American botanists. 



Mr. S afford is indebted to Dr. Barton W. Evermann, of the Bureau 

 of Fisheries, for photographs Nos. 1, 20, 22, and 44, taken by Dr. 

 Alfred G. Mayer, of the Agassiz Expedition to the Tropical Pacific, 

 while attached to the U. S. Fish Commission steamer Albatross; to 

 Mr. William Bengough for photographs Nos. 2, 7, 8, 23, and 60, taken 

 by him on the island of Guam in 1900; to Lieut. Commander J. E. 

 Craven, U. S. Navy, for photograph No. 19; to Lieut. L. M. Nulton, 

 U. S. Navy, for photographs on plate 21; to Dr. Harvey Whittaker, 

 late of the IT. S. Navy, for photograph No. 24; to Mr. B. J. Howard, 

 of the Bureau of Chemistry, U. S. Department of Agriculture, for 

 photographs on plates 9, 10 (fig. 1), 11, 12, and 13; to Mr. F. L. Lew- 

 ton, of the Bureau of Plant Industry, U. S. Department of Agricul- 

 ture, for photograph No. 35, taken in Johore for the Government 

 exhibit at Chicago; to Mr. Carl S. Scofield, of the U. S. Department 

 of Agriculture, for photographs Nos. 5, 50, and 57, taken from herba- 

 rium specimens from the island of Guam; to Mr. C. B. Doyle for 

 photographs Nos. 3, 4, 10 (fig. 2), 31, 32, 38, 40, 41, 42, 46, 47, 49, 51, 52, 

 53, 54, 56, 59, 61, 62, 64, 65, 68, from herbarium specimens, for No. 

 15 from the seed collection, and No. 14 from cultivated specimens, 

 taken under the supervision of the author, and No. 17 from specimens 

 collected in Guam by Lieut. Franck Ta3^1or Evans, U. S. Nav}^; to 

 Messrs. O. F. Cook and Guy N. Collins for Nos. 6, 25, 26, 29, 33, 34, 

 43, 44, 48, 55, 58, and 66, taken in Porto Rico, Nos. 27, 30, 36, 39, 

 taken in Guatemala, and Nos. 28 and 67, taken in Mexico; and to Mr. 

 Guy N. Collins for Nos. 16, 37, and 63, taken in the Hope Gardens, 

 Kingston, Jamaica. He is also indebted to Mr. Charles M. Mansfield 

 for photograph No. 69, taken from herbarium specimens sent to the 

 author from Guam by Rev. Jose Palomo. 



Through the courtesy of Professor Willis L. Moore, Chief of the 

 Weather Bureau, an account of the climatology of Guam is also pre- 

 sented, the detailed study of which is the work of Dr. Cleveland 

 Abbe, jr. 



FEEDEEICK V. COVILLE, 



Curator of the U. S. National Herbarium. 



