MARYLAND WEATHER SERVICE 279 



land Zone. Coniferous trees are absent except where the thin soil 

 of lower slopes favors the occurrence of occasional individuals of the 

 Hemlock. The tree species of subordinate importance are the Striped 

 .Maple, the Beech, the Sassafras, the Hornbeam, the Mountain Maple, 

 the Black Oak and the Serviceberry. The most frequent shrubs in 

 the Slope forests are: 



Hamamelis virginiana 

 Hydrangea arborescens 

 Vaccin ium vac Mans 

 Gornus alternifolia 

 Viburnum acerifolium 

 Spiraea corymbosa 

 Diervilla diervilla 

 Rhododendron maximum 

 Ribes rotundifolium. 



The absence of the Flowering Dogwood from the Mountain Zone is 

 particularly noticeable in this habitat ; its place in the physiognomy 

 of the vegetation being taken by Gornus alternifolia, which is infre 

 quent in the Midland Zone. The shrubs are scattering in the midst 

 of the forest, hut abundant in openings and along the margins. 



The floor of the forest occupying deep-soiled Slopes is extremely 

 rich in herbaceous plants, both in individuals and species, — indeed 

 there is no habitat in the state, of any character, which has a larger 

 flora. Several of the species of herbaceous plants peculiar to the 

 Mountain Zone are found here, and a much larger number which 

 occur very rarely in the Soil-covered Slopes of the Lower Midland 

 District are abundant or common. The only species which are con- 

 spicuously abundant as compared with others are Osmunda clayton- 

 iana and Dryopteris spinulosa var. intermedia. As one moves from 

 place to place in the forest the impression is given that an exacl 

 census of several small areas would give about the same figures in 

 each case for the relative abundance of the following species: 



Hydrophyllum virginicum 

 Arisaema tripliyllum 

 Trillium erectum 

 Wash ingtonia longistylis 



