MARYLAND WEATHER SEKVICE 283 



Eatonia nitida 

 Gaultheria procumbens 

 Galium lanceolatum 

 Lacinaria scariosa 

 Doellingeria umbellata 

 Geranium maculatum 

 Aralia nudicaulis 

 Silene steUata 

 Porteranthvs trifoliatus 

 Lysimachia quadrifolia 

 Hedeoma pulegioides 

 Pteris injiiiliiKt 

 Pedicularis canadensis 

 Aralia racemosa 

 Panicum capillare 

 Solidago bicolor 

 Angelica villosa 

 Hieracium paniculatum 

 Wash ington ia longistylis 

 Dasystoma laevigata 

 . I sclepias quadrifolia 

 Pogonia verticillata 

 Polygala verticillata 

 Hieracium venosum. 



At many places along the summit of Great Backbone Mountain 

 the soil overlying the sandstone rock is thin, and at other places rock 

 outcrops and gigantic boulders completely occupy the surface. On 

 I he boulders and in their crevices grow stunted trees of Sweet Birch 

 and Mountain Ash. Snch a habitat for Mountain Ash is particularly 

 surprising as the tree is elsewhere in the Zone found only in the 

 Glade and Swamp forests. Equally striking here is the occurrence of 

 Tmpatiens aurea commonly found only in flood plains and meadows, 

 and nowhere so common in the Mountain Zone as it is in the Mid- 

 land. It is probable that the porous sandstone boulders serve as 

 reservoirs of water which is fed out into the crevices, thus favoring 

 the occurrence of hygrophilous plants in a habitat which would ap- 



