748 GEOLOGICAL SUEYEY OF THE TERRITORIES. 



The plants catalogued in the present volume were all collected during 

 the season of 1872. I was attached to the party under command of 

 Captain Stevenson, and remained with it through the whole summer, 

 Up to the Fire Hole Basin, Philo J. Beveridge acted as my assistant, 

 and proved himself an active, earnest worker. Most of the collection 

 was pressed by him, and the care he always took has made handsome 

 specimens. 



In the party under the immediate direction of Dr. Haydeu, Mr. Wal- 

 ter Piatt took charge of the botanical collections, and rendered good 

 service in the region he traversed. xUthough the plants common to 

 the mountain ranges and valleys along the Yellowstone are not essen- 

 tially different from those found along Snake liiver, yet it is interesting 

 to note the fact of their existence on both the eastern and western 

 water-sheds. A slight difference can be traced, but by no means suffi- 

 ciently great to justify making two distinct floras, one of the eastern, 

 the other of the western slope. 



Collections were couimenced in tlie last of May at Ogden, Utah, 

 where our permanent camp was located until the last of June. During 

 this time a fine opportunity was afforded for studying the local flora ol 

 the i3lain bordering on Great Salt Lake, as well as that part of .the 

 Wahsatch range of mountains, near which Ogden is situated. The flora 

 of this great basin has been so thoroughly examined and described by 

 Sereno Watson in his final report that very little can be said in addi- 

 tion. Several trips were made to the shores of Great Salt Lake, and 

 collections were obtained of the flora of that peculiar region. During 

 our sta}^ of a month over three hundred species were collected, repre- 

 senting fully the June vegetation of that locality. Kepresentatives 

 were obtained from four different conditions of soil and temiierature, 

 viz, the borders of Salt Lake and its neighboring alkaline marshes; 

 the common sandy sage-brush plain, somewhat enriched here by the 

 irrigation universally practiced in Utah; the alluvial deposits along 

 Ogden and Weber Elvers ; and the mountains of the Wahsatch Eauge. 

 On the latter very few alpine plants were discovered, for a sub-alpine 

 flora clothes almost entirely the highest peaks, 



From Ogden collections were made in the latter part of June along 

 the stage-route to Fort Hall ; in July from Fort Hall to the Teton Basin 

 and western slopes of the Teton Range ; in August, up Henry's Fork to 

 Henry's' Lake, across the "Tyghee*' Pass and into the Fire-Hole Ba- 

 sins. After this date the flowering season had about passed, and only a 

 few species not before collected were noticed. Collections were made 

 in September and the first of October down the South Fork of Snake 

 Eiver, principally of plants in an advanced state of fruitage. On Oc- 

 tober 11 we closed our collections at Fort Hall, having been about five 

 months in the field. 



I would divide the plants collected into three separate and distinct 

 floras, viz : 



I. The flora of the plains from Ogden, Utah, to the Teton Basin. 



II. The flora of the Teton Range and Mountains along the Yellow- 

 stone. 



in. The flora of the Geyser Basins. 



Although a few flowers are common to all these divisions, as can be 

 seen in the following catalogue, yet the main features are very distinct. 



I. The Flora of the plains is exactly what has been so often seen and 

 described on all the vast "sage-brush '' deserts of the West. It is pecu- 

 liar to this dry, sandy region, yet much more luxuriant than one would 

 imagine from the nature of the soil. At the same time it becomes ex- 



