Vol. 3 . No. i 



TORREYA 



January, 1903 

 NOTES ON SOME SOUTHERN ILLINOIS PLANTS 



By H. A. Gleason 



During several collecting trips to southern Illinois the writer 

 has been able to make field notes on a number of rare or interest- 

 ing species. The flora of the extreme southern part of the state 

 is essentially different from that of the central and northern por- 

 tions, in that the austro-riparian flora finds there its northern limit, 

 and the unglaciated hills and vertical cliffs afford edaphic condi- 

 tions unlike anything else in Illinois. Consequently, some three 

 hundred species of the Illinois flora are confined to that region. 



The only station in Illinois for Pinus echinata Mill, is a small 

 area in Union County locally known as the Pine Hills. The soil 

 there is thin and rocky, and underlaid by Silurian limestone. 

 Erosion has cut deep ravines with steep rocky sides and sharp 

 narrow crests. These hills reach a height of four hundred feet 

 above the adjoining bottoms of the Mississippi River, or about 

 seven hundred and fifty feet above sea level. Along the narrow 

 crests of these hills the pines are growing, in company with 

 hickory and scrub oak. Some of the largest specimens are three 

 feet in diameter and eighty feet high. Along the sides of the hill 

 their growth is stunted, and none is found more than a hundred 

 feet from the crest. Cones are produced abundantly, and healthy 

 seedlings are common. 



Along the steep rocky hillside below the pines is the only sta- 

 tion in Illinois for the pink azalea, Azalea nudiflora L. The 

 shrubs are usually from three to six feet high, and are fairly 

 abundant. 



Manuals give but two stations for Phlox Stcllaria Gray — the 



cliffs of the Kentucky River and southern Illinois. The latter 



[The exact date of publication of each issue of Torreya is given in the succeed- 

 ing number. Vol. 2, No. 12, comprising pages 177-200, was issued January 8, 1903.] 



