MARYLAND WEATHER SERVICE 217 



exception to the conditions usually governing the occurrence of 

 plants outside their normal range. Other shrubs characteristic in 

 the drier Gravel forests are Vaccinium stamineum, Vaccinium penn- 

 sylvanicum, Gaylussacia resinosa, Salix tristis and Castanea pumila, 

 while in the lower and moister forests there is a richer assemblage 

 of the forms found in the Loam forests of the Coastal Plain, in- 

 cluding Clethra alnif cilia, here at the limit of its range, Vaccinium 

 corymbosum, Pieris mariana, also at the limit of its range, Xolisma 

 ligustrina, Azalea nudiflora, Viburnum acerifolium and Viburnum 

 dentatum. In the saturated gravel about the bases of the hills 

 Hamamelis virginiana is not infrequent. 



The herbaceous species which characterize the Gravel hills are 

 of a xerophilous character, and the same forms not only occur 

 throughout the Chestnut-Chestnut Oak forest in this District, but 

 in the Ridge forest of the Mountain Zone and on gravel hills of 

 morainic origin in neighboring states to the north. The common- 

 est species are: 



Melampyrum lineare 



( 'unila origanoides 



Dasy stoma pedicularia 



Andropogon virginicus 



Baptisia tinctoria 



Nabalus albus 



Lac inn riii graminifolia var. pilosa 



( 'hrysopsis mariana 



Mitchella repens 



Li n ii m medium 



Label in in /lulu 



II ieracium scabrum 



Angelica villosa 



Lechea minor 



Euphorbia corollata 



Gerardia purpurea 



Polygala nuttallii 



Knciffia fruticosa 



Smilax rotundifolia. 



