1924] PALMER, THE LIGNEOUS FLORA OF RICH MOUNTAIN 117 



frequently found in similar situations, and a southern Gooseberry (Ribet 

 curvatum) grows sparingly along rocky ledges. 



As we approach the top the trees begin to diminish in size; the woods 

 become more open and the herbaceous growth is sparser. Upon attaining 

 the summit we find ourselves on a strip of comparatively level rocky 

 ground, which may be followed for several miles east or west, but which 

 often is not more than a hundred yards in width, and sometimes narrowing 

 to a sharp rocky ridge or widening to several times its average breadth. 

 Much of the surface is strewn with sandstone rubble and boulders of dis- 

 integration. On the more level portions there is sometimes a considerable 

 accumulation of sandy soil, and small areas might even be tillable. Over 

 most of this portion there is a growth of small timber, White Oak being 

 the commonest, and in spots almost the only species. The trees are small, 

 seldom more than eight or ten meters tall, and with gnarled and twisted 

 trunks and branches, evidence of their struggle with the strong winds 

 that at most seasons sweep across these heights. Other species of less 

 common occurrence are the Blackjack, Black and Post Oaks, Mocker-nut 

 and Arkansas Hickories, Chinquapin (Castanea ozarkensis), Sassafras, 

 White Ash, Big-tree Plum {Prunus mexicana), Flowering Dogwood, 

 Persimmon and a few others. Towards the east end of the mountain, in 

 Arkansas, the Cucumber-tree is sometimes found in this summit forest, 

 and the Chinquapin is more abundant. In the more rocky portions the 

 trees give place to copse or thicket growth, in which shrubs and several 

 of the arborescent species mentioned above, but attaining only the size of 

 low shrubs, abound. Here are found several species of Plum and Haw 

 bushes, Wafer Ash, Fringe-tree or Old man's beard (Chionanthus virginica), 

 Witch-hazel, Blackberries, Buckeye {Aesculus glabra var. monticola). 

 Copal Sumac and Carolina Ilex. Occasionally there is a stunted Pine or 

 Cedar bush, and about rocky ledges grow the Juneberry (Amelanchier 

 canadensis), Gum-elastic (Bumelia lanuginosa) and two shrubby species of 

 St. John's-wort (Hypericum prolificum and H. oklahomense) . The latter 

 is much the commoner, and is very abundant in some spots. The bushes 

 sometimes reach a height of two meters, with stout spreading branches. 

 Some of the stems near the base are more than two centimeters in diameter, 

 with shredded or thinly exfoliating bark. Prairie openings and glades, 

 similar to those mentioned as occurring on Blackfork Mountain, occupy 

 small areas in the more sterile portions, especially towards the south side. 

 The grasses and small flowering plants of these open spaces belong for the 



most part to common and widely distributed species, characteristic of 

 the adjacent western prairies. 



At an early season a very distinct contrast is noticeable in the vernal 



response of the vegetation in the valley and at the top of the mountains. 



This is quite out of proportion to the difference in altitude, which generally 



is less than 1600 feet (about 500 meters). There is also a distinctly slower 



development of verdure on the south than on the north side, towards the 



