XEROPHILE HERBACEOUS PLANTS AND MESOPHILE FORESTS. 83 
near Moulton, the following prefer the slightly sheltered rocky 
shelves: 
Allionia nyctaginea. Lithospermum canescens. 
Ranunculus fascicularis. Tithospermum. tuberosum. 
Arabis laevigata. Salvia urticaefolia.} 
Claytonia virginica. Scutellaria campestris. 
Arenaria serpyllifolia. Polymnia canadensis radiata. 
Opuntia rafinesquii. Bellis integrifolia. 
Geranium maculatum.! 
Sedum putchellum 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 Hypericum aureum and H. 
sphaerocarpon' adorn the hills, giving way in the latter part of the 
season to blue and purple asters—Aster oblongifolius,' A. laevis lati- 
Jolius, A. cordifolius and others of the more commonly diffused 
species—and to the bright flowers of goldenrods, such as Solidago 
ampleaicaulis and Brachychaeta sphacelata (B. cordata 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 (Quercus acuminata), wild plum 
(Prunus americana), honey locust ( @leditsia triacanthos), hop hornbeam 
(Ostrya virginiana), 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. Grindelia 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- 
1Extends to the Louisianian area. 
