4'^0 TRANS. ST. LOUIS ACAD. SCIENCE. 



and from Ames to Nevada ; southwest to the' "Big prairie," and 

 southeast to a small "lake" about ten miles from the College. A 

 few plants have been included from the Des Moines river west of 

 Boone, eighteen miles distant ; several have also been included 

 from Cairo lake and vicinity, about twenty-two miles away. 

 But in all cases it is so stated if the plant has been found only 

 beyond the three-mile circle. 



The topography of the region presents little diversity. We 

 have: prairie, the treeless, grassy land, which has not been 

 brought under cultivation. This is fast disappearing, and in a 

 very few years none will be found except along the roadsides 

 and railways. A Irage tract known as the '^ Big prairie" lies 

 about six miles southwest of the College, just across the Boone 

 county line. Formerly this was a good collecting ground, espe- 

 cially on account of the ponds it contained, but its distinctive 

 characters have been lost as a result of close grazing and a suc- 

 cession of dry seasons. I have designated as 'Mow " or "wet 

 prairie" depressions which are wet most of the season, but not 

 sufficiently so to be called ponds. In such places may be found 

 Caltha paliistris and Cardamiiie bulbosa. 



Then there are sterile hills ^ where the soil is usually stony. 

 Such is the land northeast of the College beyond Squaw creek. 

 The hills forming the east side of the valley of Skunk river, from 

 the northwest school south to the "lake," are very sandy. Here 

 are found Cyperns filiculniis and (Enothera rhombipetala. 



The wooded portions are mostly confined to the proximity of 

 the streams, five of which are included in our region. The 

 upland xvoods are found along the bluffy side of the streams, 

 or, in case of the smaller streams, all is upland. Here are found 

 ^iiercus alba,, Hicoria ovata^ etc. Frequently near by, or often 

 at considerable distance, occur thickets or copses composed of 

 Pr units Americana., Pirus Americana,, Corylus Americana,, 

 etc. The lo-vland woods are found on the lower and moister 

 portions. Here thrive Plata/ius,, yugians, and Ulmus. Bottom 

 land is the low land along streams, especially the treeless por- 

 tion. It is subject to overflow in the spring, and later is covered 

 with a rank growth of Vernonia fasciculata, Spartina. Verbe- 



