60 FLORA OF THE YELLOWSTONE NATIONAL PARK. 



POLYGONACEJE. 



Eriogonum umbellatum, Torr. 



Grassy slopes and dry banks. Very common throughout up to 8000 

 ft. alt. 



Eriogonum heracleoides, Nutt. 



With the preceding, but less common.- 



Eriogonum flavum, Nutt. 



Common over the hot spring areas throughout. 



Eriogonum caespitosum, Nutt. 



Rocky, bare slopes. Sepulchre Mountain, 8500 ft. alt. 



Eriogonum ovalifolium, Nutt. 



Common throughout, from dry rocky ridges and benches at low eleva- 

 tions, 5400 ft. alt., to subalpine and alpine. 



Oxyria digyna, Campdera. m 



Rocky, wet places, subalpine and alpine. Swan Lake, 7400 ft. alt. 



Rumex venosus, Pursh. 



Sandy bluffs at outlet and Stevenson Island, Yellowstone Lake. 



Rumex salicifolius, Weinman. 



Sandy shores and wet meadows. Rather common. 



Rumex maritimus, L. 



Frequent in alkaline marshes. 



Rumex paucifolius, Nutt. 



Common in high meadows and bogs, 8000-9500 ft. alt. 



Polygonum aviculare, L. 



Sand beaches, Yellowstone Lake at mouth of Pelican Creek. 



Polygonum Douglasii, Greene (P. tenue, Michx.). 

 Common in dry places up to 8500 ft. alt. 



Polygonum Douglasii, var. latifolium, Greene (P. tenue, Michx., var. latifolium, 

 Engelm.). 



Rocky subalpine ridges, Bison Peak, 9000 ft. alt.; Mt. Norris, 8000 

 ft. alt. 



Polygonum imbricatum, Nutt. 



Moist places. Blacktail Deer Creek, 7400 ft. alt. ; Slough Creek, 6600 

 ft. alt. ; East Pelican Creek, 8400 ft. alt. Frequent. 



