August. 1955 



EvERs: Hill Prairies of Illinois 



413 



Government Rock. — Located in the 

 southeast quarter of section 9, T. 11 S., 

 R. 3 W., 4.5 miles north of the village of 

 Wolf Lake. Union County, this hill prai- 

 rie, when visited, occupied one of the siz- 

 able spurs which extends from the sum- 

 mit downslope to the rock cliff in that 

 portion of the Mississippi bluffs known as 

 Pine Hills. The appellation here used — 

 Government Rock — is the one applied to 

 this spur on the ^Volf Lake sheet of the 

 topographic map. 



Above the clift at the base of the spur 

 is a steep west- and southwest-facing 

 slope strewn with chert stones. When last 

 seen, the lower part of the slope was oc- 

 cupied by a thin stand of undersized 

 trees. Above this was prairie, dominated 

 by Jndropogon scopariiis and Bouteloua 

 curtipendula. A few small trees of Quer- 

 cus muhlenbergii, Ostrya rirt/iniana, Ju- 

 niperus virginiana, and / irhurnum rufidu- 

 lum occurred in several open groups 

 within the prairie. 



Upslope on the spur was a strip, about 

 20 feet wide, with fewer prairie plants 

 and an abundance of Tephrosia virgini- 

 ana. This strip was followed by a zone 

 of mixed upland forest, which included 

 Quercus muhlenbergii, O. stellata. Sassa- 

 fras alhidum, Juglans nigra, Carya spp., 

 Cercis canadensis, and some large trees 

 as well as seedlings ot Pinus echinata. 

 facciuiurn arboreum and Ceanothus 

 americanus were common shrubs. 



The uppermost part of the spur, which 

 was capped by loess, was occupied by prai- 

 rie vegetation. The narrow ridge-top had 

 been much disturbed by picnickers. The 

 east-facing slope of the bluff-ridge was 

 forested nearly to the ridge-top. 



Government Rock was visited October 

 27. 1^49; August 17 and October 16, 

 1950: April 19 and May 23, 1951. 



Tanims. — This hill-top prairie open- 

 ing, about a half acre in area and located 

 on the crest of a cherty ridge in the south- 

 east quarter of section 35, T. 14 S.. R. 

 2 W.. 1 mile west and 1 mile north of 

 Tamms. Alexander County, was visited 

 September 20. 1950. The prairie area, 

 containing such plants as Jndropogon 

 gerardi, Solidago nemoralis, and Helian- 

 thus divaricatus, was surrounded by a 

 woodland of xeric oaks, hickory, and some 



sassafras. One of the oaks on this ridge 

 was QiienuK. r/iontana. 



Cave Creek. — When this area was 

 last visited, a rock (limestone) hill prai- 

 rie occupied part of the blui? on the east 

 side of the confluence plain of Dutchman 

 and Cave creeks, somewhat over a mile 

 east of the Cache River, in the northeast 

 quarter of section 28, T. 13 S., R. 3 E., 

 about 5 miles south of X'ienna and 1.5 

 miles northeast of Forman, Johnson 

 County. The base of the blul? was 

 wooded, but it had been much disturbed 

 during the construction of a power line. 

 The prairie opening above the disturbed 

 wooded bluff base occupied about 1.5 

 acres of the south- and southwest-facing 

 slope of the ridge. The prairie slope was 

 strewn with rock fragments which had 

 eroded from outcrops at various levels 

 on the slope. In some places the slope 

 was almost a rock pavement. Grasses and 

 composites were the predominant vege- 

 tation ; a few small trees of Quercus 

 muhlenbergii, Juniperus virginiana, Cor- 

 nus florida. and Crataegus spp. were 

 found scattered throughout. The trees 

 did not reach full size; after they had at- 

 tained heights of 10 to 15 feet the tops 

 lost vigor and the trees died. 



Upslope from the prairie, the broadly 

 rounded ridge was forested, but it had 

 openings occupied chiefly by .4 ndropogon 

 gerardi. An interrupted limestone ledge 

 traversed this forested surface. Much 

 Xothoscordum bivalve grew in the crev- 

 ices of this ledge. 



Cave Creek prairie was visited June 10, 

 August 17. and September 20, 1950; 

 April 18 and May 22, 1951. 



FLOR.A OF THE HILL 

 PRAIRIES 



As a means of determining what spe- 

 cies of plants occur in Illinois hill prai- 

 ries, numerous collections were made from 

 early September, 1949, to the middle of 

 October, 1951. Many of the plant spe- 

 cies very common in Illinois were col- 

 lected from only one prairie but their oc- 

 currence in other prairies was recorded 

 in the field notes. Species less common 

 were collected from each prairie site in 

 which they were growing. More than 



