378 



Illinois Natural History Survey Bulletin 



Vol. 26, Art. 5 



and loess slopes. The Phegley prairie 

 was pastured ; the Sampson was not. 

 Thus, it was possible to compare pastured 

 and unpastured prairie slopes in the same 

 locality. 



Because Phegley and Sampson prairies 

 were accessible to the writer by automo- 

 bile, no laborious and time-consuming 

 ascent from the bottomland, up the basal 

 slopes and over the nxk ledge, was neces- 



sary; steep climbs are necessary to attain 

 the majority of hill prairies in Illinois. 



Study Procedures. — For detailed veg- 

 etation studies in hill prairie, the upper 

 slopes of spurs seemed to be the best sites 

 because these slopes had a vegetation that 

 was nearly "pure" prairie, and they had 

 surfaces that showed little erosion. The 

 steep spur fronts, figs. 6 and 7, contained 

 species characteristic of prairie but showed 



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Fig. 8. — A l-milacre quadrat in the pastured Phegley hill prairie, charted October 9 and 

 10, 1951, by A. G. Vestal and R. A. Evers. .A, Andropognn scoparius; S, Solidago nemoralis; 

 1, Lespedcza stipulacea; B, Bouteloua curtipenduta; G, Gerardia sp.; V. Pctalostemum pur- 

 pureum; H. Houslonia nigricans; D, Desmodium riliarf, L, Lespedfza capitala; E, Euphorhia 

 coroUata; f. Cassia fasciiulata; J, Junipcrus -virginiana; Is, L/num sulcatum; N, Srnrcio plat- 

 tensis; v, Polygala -verlicillata; and d, Hedeoma hispida. 



