48 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



practically unknown regions of the interior. It is from the latter 

 regions mainly that additions to the Alaskan flora are to be expected 

 in the future. It has been impossible to determine the habitat of 

 many of the species herein enumerated, as most collectors have neg- 

 lected to furnish any data other than the locality and date of collec- 

 tion. Notable exceptions to this general lack of data are found in the 

 fine collections made by W. H. Evans during the years 1897 and 1898, 

 and by F. H. Walpole in 1901. 



Under critical species are cited the specimens, found in the U. S. 

 National Herbarium, upon which the enumeration is based. These 

 include those from Alaska and also those from the adjacent Yukon 

 Territory of the Dominion of Canada, the flora of which, by the course 

 of the Yukon River, is rendered geographically continuous with the 

 former. The following are some of the more important of the collections : 

 C. Wright, 1853-1856; A. Kellogg, 1868; M. W. Harrington, 1871-72; 

 L. M. Turner, 1880; C. L. McKay, 1881; Doctor Murdock, 1882; 0. S. 

 Bates, 1889; C. Hart Merriam, 1891; W. G. Wright, 1891; J. M. 

 Macoun, 1891, 1896, 1897; B. W. Evermann, 1892; Frederick Fun- 

 ston, 1892; Thomas Howell, 1895; W. II. Evans, 1897, 1898; R. S. 

 Williams, 1899; E. F. Glenn, 1899; F. C. Schrader, 1899; J. B. Tarle- 

 ton, 1899; C. C. Georgeson, 1898, 1900; F. E. Blaisdell, 1900; J. B. 

 Flett, 1900; F. A. Walpole, 1901; C. V. Piper, 1904; and the mate- 

 rial secured by the Harriman Alaskan Exploring Expedition, 1899, 

 by the following botanists: Frederick V. Coville and Thomas II! 

 Kearney; William Trelease and De Alton Saunders; W. H. Brewer 

 and W. R. Coe; T. Kincaid; and L. J. Cole. In addition to these col- 

 lections, we have had a few specimens from the earlier Russian col- 

 lectors, representing several of Trinius's species, and some from other 

 collectors whose names are given wherever their specimens are cited. 



The systematic distribution of the Alaskan grasses as a whole is 

 very interesting. At this date not a native or introduced species of 

 the series Panicaceae is known from Alaska, the tribes Maydeae, 

 Andropogoneae, Osterdamieae, Tristegineae, Paniceae, and Oryzeae 

 being thus eliminated, while on the other hand all the tribes of the 

 series Poaceae are represented except the Bambuseae. Of these tribes 

 Phalarideae has one genus, Savastana; Agrostideae, 9 genera, Stipa, 

 Phleum, Alopecurus, Phippsia, Arctagrostis, Cinna, Agrostis, Poda- 

 grostis,and Calamagrostis ; Aveneae, 3 genera, Deschampsia, Trisetum 

 and Avena; Chlorideae one genus, Beckmannia; Festuceae, 10 genera, 

 Catabrosa, Melica, Dactylis, Poa, Colpodium, Dupontia, Panicularia| 

 Puccinellia, Festuca, and Bromus, while Hordeae has 3 genera, Agro- 

 pyron, Hordeum, and Elymus. The genus Poa is represented by the 

 greatest number of species. Under the 27 genera considered there 

 are here enumerated and described 104 species and 18 subspecies. 

 There are 10 species proposed as new to science. 



