4 B Canadian Arctic Expedition, 1913-18 



in Elymus, Poa abbreviata, Festuca rubravar. arenaria, etc.; it is awned in Alope- 

 curus, Trisetum, Festuca, Bromus, and in Hordeum the awn reaches a considerable 

 length, up to about four cm. In habit these arctic Gramineae do not exhibit any 

 characteristics which might indicate the extreme conditions under which they 

 live. The same observation I have made with respect to the alpine species, 

 notably in the Rocky mountains, Colorado, several of which do not recur in the 

 lowlands. Even the peculiar genus Pleuropogon with its rather large, drooping 

 spikelets forming a simple, loose raceme, and of which one species,' P. Sabinii 

 R. Br., is almost circumpolar, is also represented in California by P. refractum 

 Benth. and P- californicum Benth. 



As compared with the species known from the arctic American archipelago ' 

 there are only a few types which were not found by the Canadian arctic 

 expedition, for instance: Hierochloa alpina, Agrostis, Deschampsia, Catabrosa, 

 and Pleuropogon, some of which are widely distributed in the arctic regions. 

 But since Mr. Johansen succeeded in finding several of the small and much 

 more inconspicuous species of Carex, there is no reason to believe that the 

 "missing" species of grasses were overlooked. 



Arctagrostis latifolia (R. Br.) Griseb. 



I have without hesitation referred all the specimens collected by the Cana- 

 dian expedition to this species although those from Camden bay, Herschel 

 island, and Bernard harbour do resemble A. arundinacea (Trin.) Beal, as far as 

 the panicle being more open and the spikelets less compact. According to 

 Grisebach in Ledebour's Flora Rossica (p. 434) A. arundinacea is considered 

 merely a variety of A. latifolia: "panicula laxiori, palea inferior! (the flowering 

 glume) obsolete 5-nervi." Recently, by Scribner and Merrill,^ this variety is 

 enumerated as a species with no other distinctive characters than "the branches 

 of the panicle being fasciculate, spreading or ascending," besides some measure- 

 ments of the culm, leaf, and spikelets. However, judging from the large material 

 which I have examined from the northern regions of both Worlds, there seems 

 to be no doubt of the genus being monotypic, although very variable. Specimens 

 from Siberia, viz: Jenisei, Dudino, thus represent the typical plant as well as 

 the variety, and they were found growing associated with each other; in several 

 specimens of gigantic size from Jakutsk, Siberia, the panicle is very open and 

 the spikelets comparatively small, but the structure of both the empty and the 

 flowering glumes shows no deviation from that of the typical plant; similar 

 specimens from Yukon and St. Paul island, Bering sea, differ in no respect from 

 the type except by their greater size, the more open panicle, and the smaller 

 spikelets. And in this respect Arctagrostis agrees with species of several other 

 genera, for instance with Deschampsia caespitosa, as represented in the alpine 

 region, the arctic, and the lowlands much farther south; furthermore, in Festuca 

 ovina and in many species of Poa the panicle may be more or less contracted 

 and the spikelets varying considerably as to size and number of flowers. 



Poa abbreviata R. Br. and P. glauca M. Vahl. 



Small forms of P. glauca may sometimes be mistaken for P. abbreviata. 

 Lange' describes both, calling attention to the characters as follows: P. abbreviata 

 R. Br. "Humilis, densissime caespitosa; foliis rigidiusculis, subsetaceo-involutis, 

 acuminato-pungentibus, margine scabriusculis, ligula brevi, obtusiuscula; pani- 

 cula brevi, simplicissima, subsecunda, ramis in verticillis c. 2 plerumque spiculam 

 solitariam, 3-5-floram gerentibus; glumis acutis, inaequalibus; gluma florens 

 (palea inf.) obovata, trinervia, puberula et infeine longius villosa, obtusissima 

 v. truncata, eroso-denticulata." 



> Simmons, H. G. A Survey of thePhytogeograpUy of the Arctic Amerioaa Archipelago. (Lunds 

 Univers. Arsakr. Aid. 2. Bd. 9. Lund, 1913.) 

 . > Grasses of Alaska, 1910. 

 ' Conspectus Florae Groenlandicae (Medd. om Gr^nland, Kj^benhavn, 1880). 



