August. 1955 



EvERs: Hill Prairies of Illinois 



415 



Illinois (Pope County I, apparently it is 

 absent from similar situations in the 

 Fountain Blutt hill prairie. 



Equisetaceae 



Ef/itisetuin hyemale L. The tall scour- 

 ing-rush was seen in three hill prairies. 

 Rock Island 31, Bunker, and Southwest 

 Edgemont, where it occurred in loess. It 

 was not seen on rocky slopes. 



Equhetuni laevigatum A. Br. [£. kan- 

 sanum Schaftn.] The smooth scouring- 

 rush was observed in seven bluff prairies, 

 all of them in northern or central lUi- 



POLYPODLACEAE 



Cheilanlhes lanosa (Michx.) D. C. 

 Eaton. The woolly lip-tern was found in 

 rock prairie at Cave Creek. It was more 

 abundant, however, on rock outcrops than 

 on prairie slopes. 



Pellaea atropurpurea (L.) Link. Al- 

 though the usual habitat for purple cliff- 

 brake is calcareous rocks, it occurred on 

 the loose stony slopes at Cave Creek and 

 Government Rock. 



PiNACEAE 



J uniperus virginiana L. Red cedar was 

 found in both rock and loess hill prairies 

 and was common on rock ledges at the 

 bases of prairie slopes ^ and in wooded 

 coves. It was the only tree species on 

 some of the prairie slopes. Steyermark 

 (19401 noted its frequent occurrence in 

 Missouri glades. 



Gramikeae 



Jgrostis hiemalis (Walt.) B.S.P. 

 Ticklegrass was encountered only in rock 

 prairie at Fountain Bluff. 



.iniiropot/on gerardi Vitman. [A. fur- 

 catus Muhl.] The big bluestem is an 

 abundant prairie grass in Illinois. It was 

 observed in 37 hill prairies. It was found 

 as a dominant only in scattered patches, 

 and in this status in only a few hill prai- 

 ries. 



Andropogon sioparius ^lichx. Little 

 bluestem was found to be the usual dom- 

 inant and is the most important grass of 

 the hill prairies of Illinois. 



Andropogon virginicus L. Broomsedge, 

 a common grass in open woods, old fields. 



and along roadsides in southern Ilh'nois, 

 was not foui»;I to be an important species 

 of the hill prairies, ha\ing been seen in 

 but one. Fountain Bluff, on the loess prai- 

 rie slopes. 



Aristida basiramea Engelm. e.\ N'asey. 

 This plant was collected in only the Sun- 

 set Trail hill prairie. 



Aristida intermediti Scribn. ^ Ball. 

 This was observed only at Hill-Top and 

 in the sandy prairie at Devil's Backbone. 



Aristida longesptca Poir. This three- 

 awned grass was collected in prairie at 

 Devil's Backbone and from a rock ledge 

 at Cave Creek. 



Aristida oligantlia Michx. This weedy 

 species was collected in only the Seehorn- 

 Pa\son hill prairie. 



Boiiteloua lurtipendiila (Michx.) 

 Torr. Side-oats grama was found in 48 

 of the hill prairies examined. In southern 

 Illinois, it was found in Cave Creek and 

 Government Rock prairies, but it was 

 not observed at Tamms, Fountain Bluff", 

 or Grand Canyon. It was seen at most 

 of the sites examined from Allen Lake 

 northward along the Mississippi and Illi- 

 nois rivers. Vestal (1945) mentioned 

 "hill prairie and sandstone cliff-tops" as 

 common habitats of this species in Illinois. 

 He observed in July, 1*^41. that this Bou- 

 teloiia dominated several steep southwest 

 slopes of prairies along the lower Illinois 

 in Jersey County, sites not included in 

 this study. Side-oats grama was the dom- 

 inant grass just above the rock ledge at 

 Swarnes; a few feet higher on the prairie 

 slope, A ndropogon scoparius was domi- 

 nant. 



Boutfloua hirstita Lag. Hairy grama 

 was observed in eight hill prairies, most of 

 them in northern Illinois. It grew in the 

 heavilv pastured loess prairie at Bald 

 Bluff" and also along the bluffs of the Illi- 

 nois River at Mud Creek and Northeast 

 Meredosia in central Illinois. 



*Bromus lommutatiis Schrad. Hairy 

 chess was found in loess and rock prairie 

 at five sites and in crevices of rock ledges 

 at two others. 



*Bromus teiloruni L. Down\ chess 

 or cheat was found in situations similar 

 to those of hairy chess. It was more abun- 

 dant in crevices of rock ledges than in 

 hill prairie. 



