19211 PALMER, BOTANICAL RECONNAISSANCE OF SOUTHERN ILLINOIS 145 



Hydrangea arhorescens L. A common shrub on steep banks and hill- 

 sides in the Mounds Formation, and also along shaded rocky bluffs in 

 the Ozark Ridge Formation. Not seen in the Cairo region. 



Hydrangea cincrea Small. Apparently less common than the last, and 

 noted only along rocky bluffs in Pope and Hardin Counties. 



Ilea virgimca L. Strictly local in the deep swamps of the Cairo For- 

 mation, where it often grows on rotting logs. 



Ribes gracile Michx. Seen only along rich rocky hillsidei in the Pine 

 Hilb of Union County, where it is not abundant. 



Liqnidamhar Slyraciflua L. A common forest tree, except in the Ozark 

 region, where it is comparatively scarce and confined to the vicinity 

 of streams and bluffs. In the Cairo Formation it often grows in deep 

 swami)s with Tupelo and Cypress, but is more abundant in the rich 

 alluvial bottoms. It also forms an important part of the forest in the 

 Mounds Formation, where it attains a very large size. 



Platanus occidentalis L. Rather frequent on banks of streams through- 

 out the region, except in the Cairo Formation, where it is rarely seen. 



Mains coronaria (L.) Mill. Frequently found throughout in thickets 

 and open woods of bottoms and hillsides. Some very large specimens 

 were seen on slopes of the "Wild Cat Hills,'' near Equality, Gallatin 

 County. While no measurements were taken, the largest specimens were 

 estimated at 10 or 12 metres tall, and more than 3 decimetres in diameter 



of trunk. 



Mains loensis (Wood) Britt. Often found in similar situations as 

 the last; and occurring throughout the region. Rare in the Cairo For- 

 mation, and most common northward. 



Mains landfolia Rehd. Medium-sized trees found in low woods near 

 Shawncetown, Gallatin County, and Elizabethtown, Hardin County, 

 appear to belong to this species. 



Mains angusiifolia Michx. This southern Crab Apple is found in open 

 upland woods and on rocky slopes and river banks in Johnson and Pope 

 Counties. In the dryer situations it is a shrub or small tree, rarely more 

 than 2 or 3 metres tall; in richer soil below the rocky bluffs of the Ohio 

 River near Golconda, arborescent specimens 6 or 8 metres tall were found. 

 The bark of these trees is dark, comparatively smooth, and not shaggy 

 as in the preceding species; and the small ovate pointed leaves are very 

 characteristic. This plant, like a few others, such as Crataegus phaeno- 

 pyrnm and Robinia Pseudoacacia, seems to have entered the region 

 from the southeast, having by some means crossed the barrier of the 

 broad valley of the Ohio River from the southern Appalachian foot- 

 bills. 



Amelanchier canadensis (L.) Medic, Frequently found along rocky 



Mound 



Formation. 



Rubus occidentalis L. The wild Raspberry is most abundant in the 

 Mounds Formation, and is occasionally found along rich bluffs and hill- 

 sides in the Ozark Ridge region. 



