61 



Grayia spinosa Moqiiin. (Spiny-sage). — A branched, spiny shrub, with oblong, 

 thick, succulent leaves. It produces enovuious fjuantities of flat, wiuged seeds. 

 These, with the leaves, fall early, and are collected by the wind into little drifts 

 or inlea under the bushes and in the hollows of the ground. When sheep are 

 fed over the ground these leaf piles are the first to disappear. Abundant on the 

 slopes of the hills adjacent to Bitter Creek and its tributaries. Green River, 

 May 30 (3029) ; Bitter Creek, July 12 (3698). 



Dondia diffusa Heller. — A small, succulent annual, a few inches in height; com- 

 mon on wet alkali flats. I'robably of small forage value. South Butte, July 13 

 (3749). 



Dondia multiflora Heller (Shrubby Blitp:).— A small plant with numerous suc- 

 culent stems from a woody base, G to 12 inches high ; common in alkali basins 

 and on the banks of Bitter Creek. Its forage value unknown. Green River, 

 May 31 (3042). 



Salsola tragus L. (Russian Thistle.)— A much-branched, succulent spiny annual, 

 becoming a tumbleweed when mature. It is still rare in the desert. Observed 

 only at Rock Springs and Green River. 



NYCTAGINACEiE. 



Abronia sp. — Probably a new species, but lacking fruits, without which it can not 

 be sullicieutly characterized for publication. On the dry bluffs. Green River, 

 May 30 (3021). 



CARYOPHYLLACEiE. 



Silene menziesii Hook. (Menzies's Pink). — A small, leafy, branching perennial, 

 growing on wet banks, varying in height from a few inches to a foot. Observed 

 but once in the desert. Bitter Creek, July 12 (3532). 



Arenaria congesta Nutt. (Bunch Sandwort).— A small, erect plant, growing in 

 bunches 4 to 6 inches high, with grass-like stems and leaves, and bearing a 

 globular head of flowers. It is not known whether this is eaten by stock. Very 

 abundant ou some of the sage-brush sIojjcs in the desert. South Butte, July 13 

 (3732). 



Arenaria hookeri Nutt. (Hooker's Sandwort).— A strongly matted plant, only a 

 few inches high, with rigid, pointed leaves and white, star-like flowers. Com- 

 mon on dry, rocky points. Green River, June 1 (3069). 



Arenaria nuttallii Pax. (Nuttall's Sandwort). — A low plant with spreading stems 



and pointed leaves, occasional on the driest, shaly slopes. Green River, May 31 



(3054 J. 



RANUNCULACEiE. 



Oxygraphis cymbalaria Prantl. (Seaside Crowfoot or Buttercup).— A low, 

 smooth buttercup, si)readiug by runners; common on wet or marshy saline 

 soil everywhere. Noted in very many places in the desert. 



CRUCIFERiE. 



Stanleya pinnata Britton.— Erect, with entire or incised leaves, 2 to 3 feet high; 



flowers yellow, in a long spike. Green River, May 30 (3034). 

 Stanleya pinnata integrifolia Robs.— Somewhat similar to the preceding, but with 



all the leaves entire. Rock Springs, July 25 (3.596). 

 Thelypodinm sp.— A slender, branching form, occasionally seen on the Green River 



blufls ; the species not yet determined. May 30 (3034o). 

 Lepidium medium Greene (Western Peppergrass). — A much-branched annual, 



6 to 12 inches high. Flowers very numerous, inconspicuous. Abundant in some 



of the sandy draws of the desert. Point of Rocks,- June 1 (3092). 

 Lepidium montanum Nutt. (Large-flowered Peppergrass). — Tufted perennial 



with numerous stems, 4 to 8 inches high; petals white and unusually large for 



the genus. It seems to jjrefer saline soil. Bitter Creek, June 2 (3106). 



