Prairie Flora 365 



tanica, is conspicuous. Polygonom lapanthi folium is common on 

 moist grounds, while Polygonum emersum shows its dense rose-colored 

 spikes in the deeper sloughs. This last mentioned plant when touched 

 by the autumnal frosts gives forth a spicy fragrance never to be for- 

 gotten by one who has once inhaled it. Beckmannia crucaeformis is 

 blooming in muddy places, or more generally growing out of the 

 water. Ranunculus macounii may now by looked for on moist ground. 



Early in September Helenium autumnale and Solidago graminir 

 folia open their yellow heads on ground that has been wet all summer. 

 The mininutive EleocUaria acicularis is growing in muddy places cov- 

 ering the ground like a carpet. Am.hrosia psilostachya is now found 

 in moist places. Boltonia asteroides is in bloom on all wet grounds, 

 and its white star-like flowers do much to make the low lands look 

 as white as the upland prairie where Aster multiflorus is in bloom. 

 Aster paniculatus is found in the same low sloughs. The later 

 autumnal flowers of low ground are Bidens frondosa, Bidens leavis 

 and Artemisia biennis, and soon frost puts an end to the whole prodigal 

 show. 



3. The Prairie Meadow Flora. 



The earliest of prairie grasses, Hierochloe odorata, has already 

 been referred to. This grass matures so early as not to be an im- 

 portant constituent of the pr2iirie meadows. Poavcompressa has been 

 occasionally found, but is by no means common. A tall Poa collected 

 at Clara City was identified at Poa pseudopratensis by Prof. Scribner. 

 Poa pratensis is not often found in a natural meadow, but it is crowd- 

 ing out the native grasses by road sides and in pastures. Panicum 

 scribnerianum is quite common in prairie meadows early in June; 

 but it ripens early and does not contribute much to the hay crop. 

 Agrostis alba, seemingly native, is quite common, but much more com- 

 mon is Poa tri/lora, a grass that forms a large part of the hay of 

 prairie farmers. Among the weeds in the native meadows, must be 

 classed Hordeum jubatum, sl grass that seems to be more .than main- 

 taining itself. It furnishes good pasture early in the season, but 

 its rough barley-like awns are very injurious to stock and often cause 

 great damage to the hay crop. Among the coarser grasses of the 

 prairie meadow is Spartina cynosuroides, growing to the height of 

 from three to five feet. Echinochloa crua-galli is found blooming in 

 August in the wetter parts of the prairie meadows. In many mead- 

 ows the bulb-producing wild onion. Allium canadense, is common. 



//. The Alkali Flat Flora. 



On some western Minnesota prairies the soil is strongly impreg- 

 nated with alkaline salts, especially where the surface is so level that 

 the drainage is poor. In such places it would seem that "lye" from 

 the ashes left from frequent burning of the prairies has accumulated 

 until few plants can survive the trying conditions. On these flat 

 prairies Astragalus hypoglottis, looking strangely like red clover, is 

 frequently found. This is a circumpolar plant, and extends in similar 

 locations across the steppes of Siberia. It is occasionally found in 

 valley lands. Another plant of these locations is the common louse- 

 wort, Pediciilaris canadensis. One might conclude from the notation 



