August, 1955 
Illinois (Pope County), apparently it is 
absent from similar situations in the 
Fountain Bluff hill prairie. 
EQUISETACEAE 
Equisetum 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. 
Equisetum laevigatum A. Br. [E. kan- 
sanum Schaffn.] The smooth scouring- 
rush was observed in seven bluff prairies, 
all of them in northern or central IlIli- 
nois. 
POLYPODIACEAE 
Cheilanthes lanosa (Michx.) D. C. 
Eaton. The woolly lip-fern 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 
Juniperus 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 
(1940) noted its frequent occurrence in 
Missouri glades. 
GRAMINEAE 
Agrostis hiemalis (Walt.) B.S.P. 
Ticklegrass was encountered only in rock 
prairie at Fountain Bluff. 
Andropogon gerardi Vitman. [d. 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 scoparius Michx. 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, 
Evers: Hitt Prairiss or ILLINoIs 
415 
and along roadsides in southern Illinois, 
was not found to be an important species 
of the hill prairies, having been seen in 
but one, Fountain Bluff, on the loess prai- 
rie slopes. 
Aristida basiramea Engelm. ex Vasey. 
This plant was collected in only the Sun- 
set Trail hill prairie. 
Aristida intermedia Scribn. & Ball. 
This was observed only at Hill-Top and 
in the sandy prairie at Devil’s Backbone. 
Aristida longespica Poir. This three- 
awned grass was collected in prairie at 
Devil’s Backbone and from a rock ledge 
at Cave Creek. 
Aristida oligantha Michx. This weedy 
species was collected in only the Seehorn- 
Payson hill prairie. 
Bouteloua  curtipendula (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, 1941, that this Bou- 
teloua 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, Andropogon scoparius was domi- 
nant. 
Bouteloua hirsuta Lag. Hairy grama 
was observed in eight hill prairies, most of 
them in northern Illinois. It grew in the 
heavily pastured loess prairie at Bald 
Bluff and also along the bluffs of the I]li- 
nois River at Mud Creek and Northeast 
Meredosia in central Illinois. 
*Bromus commutatus Schrad. Hairy 
chess was found in loess and rock prairie 
at five sites and in crevices of rock ledges 
at two others. 
*Bromus tectorum L. Downy 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. 
