XEEOPHILE HERBACEOUS PLANTS AND MESOPHILE FORESTS. 83 



near Moulton, the following prefer the slightly sheltered rocky 

 shelves: 



Allionia nyctaginea. Lithospermum canescens. 



Ranunculus fasdoalaris. Lithospermum tuberosum. 



Arabia laevigata. Salvia urticaefolia. 1 



Claytonia virginica. Scutellaria campestris. 



Arenaria serpyllifolia. Polymnia canadensis radiata. 



Opuntia rafinesquii. 1 Bellis integrifolia. 

 Geranium maculatum. 1 



Sedum pulchellum and Phacelia purshii adorn the interstices of the 

 rocky fragments, and Arenaria patula the bare rocks. During the 

 first summer months the golden flowers of Ifypericum aureum and H. 

 sphaerocarpon l adorn the hills, giving way in the latter part of the 

 season to blue and purple asters Aster oblongifolius^ A. laevis lati- 

 folius, A. cordifolius and others of the more commonly diffused 

 species and to the bright flowers of goldenrods, such as Solidago 

 amplexicaulis and Brachychaeta sphacelata (B. cor data Torr. & Gr.), 

 which are confined to the lower southern Appalachian ranges. 



West of the spurs of the Cumberland highlands isolated knolls rise 

 above the wide river plain with its seemingly interminable fields of 

 cotton, corn, and small grain. These hillocks, of a siliceous limestone 

 which has resisted erosion, support with their scanty covering of soil 

 a stunted growth of chinquapin oak (Quercm acuminatci), wild plum 

 (Prunus americana), honey locust ( Gleditsia triacanthos), hop hornbeam 

 (Ostryavirginiand), and shrubs common on dry calcareous soil, and are 

 frequently destitute of large trees. The plants which find a refuge in 

 these localities form an interesting combination of xerophile, campes- 

 trian, and sylvan associations. Under the shades of the denser clumps 

 of the low trees have been noted: 



Poa sp. Dentaria laciniata. 



Leptorchis liliifolia. Meibomia pauciflora. 



Cypripedium parviflorum. Mertensia virginica. 

 Delphinium tricorne. 



In exposed places the following species of the open plain have estab- 

 lished themselves: 



Arenaria patula. Euphorbia obtusata (rare) . 



Isanthus brachiatus. Kuhnistera gattingeri. 



Anemone caroliniana. Gnndelia lanceolata. 



Hypericum prolificum (frequent) . Amphiacharys dracunculoides. 



The Kuhnistera is rendered attractive by its numerous spikes of 

 rose-purple flowers. The last two are remarkable outposts, if not waifs, 

 from the plains west of the Mississippi River. 



Mesophile forests. North of the Tennessee River the detached spurs 

 of the Cumberland Mountains, capped with the sandstones and con- 



1 Extends to the Louisianian area. 



