1924] PALMER, THE LIGNEOUS FLORA OF RICH MOUNTAIN 113 



slope, until the accumulation from different levels completely covered up the 

 ledges and serve to protect them from further disintegration. The surface 

 of these rock slides is often almost entirely barren of vegetation. A few 

 herbs and shrubs, however, sometimes find foothold amongst the clefts. 

 The little fern, Polypodium polypodioides Hitchc, frequently grows on the 

 north faces of large boulders amongst the lichens and mosses. Stunted 

 trees and shrubs cling to the margins and occasionally appear in spots 

 where there is a little accumulation of finer material. Quercus marilandica, 

 Crataegus spathulata and Castanea ozarkensis are frequently found in 

 such situations. Over the greater portion of the mountain side, where 

 the slope is not too steep for the accumulation of some soil, is found a 

 rather open forest, in which the Pine (Pinus echinata) attains the largest 

 size and generally far overtops the deciduous trees. Amongst the common- 

 est species of the latter class here are Carya alba, C. Buckleyi var. arlcansana, 

 Quercus alba, Q. stellata, Q. velutina, Q. marilandica, Q. borealis var. maxima 

 and Robinia Pseudoacacia. Smaller trees and shrubs growing here are 

 Ostrya virginiana, Ulmus alata, Celtis pumila var. georgiana, Sassafras 

 officinalis, Quercus Muhlenbergii, Crataegus apiifolia, C. pagensis, Rubus 

 Andrewsianus, Rhus Toxicodendron, Acer rubrum, Cornus florida 9 Vac- 

 cineum arboreum y V. stamineum, Bumelia lanuginosa and Viburnum 



rufidulum. Where the slope is somewhat steeper, or where for some other 

 reason the forest has not been able to take possession, there are thickets 

 composed largely of shrubs and a few herbaceous species. These give 

 place in spots to open rocky glades, where the flora is of a more xerophytic 

 character, and to small areas where there is scarcely any ligneous growth, 

 and upon which a grassy prairie flora prevails. The low and high Bush 

 Huckleberries (Vaccinium vacillans var. crinitum and V. stamineum) abound 

 in these thickets, as well as small specimens of the Tree Huckleberry (V. 

 arbor eum). Often also there are stunted specimens of the Black Locust, 

 Blackjack, Post Oak, and small Plum and Haw bushes of several species. 

 Amorpha glabra frequently grows here and in the edges of the glades, where 

 it becomes a tall shrub from one to two meters in height. Amongst the 

 rocks, where it has few competitors except the low Huckleberry, there 

 are often large colonies of little spiny Rose {Rosa subserrulata) . Yucca 

 glauca is sometimes found in the glades, with Agave virginica L., Opuntia 

 humifusa, Hypericum cistifolium and other plants of similar habitat. Here 

 also was first noticed an unknown species of St. John's-wort, which is de- 

 scribed in another part of this paper as Hypericum oklahomense. On the 

 open rocky slopes and in' the glades it is a low branching shrub, usually 

 under half a meter in height, but in more favorable situations it becomes 



much taller. 



Well up towards the top of the mountain and on its level summit the 



prairie openings are best developed. Such grasses as species of Andropogon, 



Sporobolus and Sorghastrum flourish here. There are scarcely any woody 



plants, except for a few low Huckleberry bushes and occasionally the little 



