MAEYLAND WEATHER SERVICE 209 



ROCKY SLOPES. 



The steeper slopes on which the soil is thin or confined to pock- 

 ets in the rocks bear a markedly different vegetation from the 

 gentler and soil-covered slopes. The trees may be pure stands of 

 Chestnut Oak or stands of Chestnut Oak with a smaller percent- 

 age of Chestnut, or again, where the slopes are precipitous, the 

 Scrub Pine may be more abundant than either. On the rocky 

 slopes of the Gunpowder and other large streams the Hemlock is 

 not infrequent, and the White Oak and the Black Oak may be 

 present with these trees. The Juneberry (Amelanchier canadensis) 

 is a small tree common on all rocky slopes, and most conspicuous at 

 its flowering time in the last weeks of April. Thickets of Kali)} in 

 laHfolia often cover the slopes which afford sufficient soil, with 

 \ actinium stamineum in less abundance. The herbaceous vegeta- 

 tion is poor in species in comparison with any of the other hab- 

 itats of the district excepting the gravel, and is indeed similar 

 to that found on the gravel hills. Among the commoner species 

 may be mentioned: 



Mitchella repens 

 Epigaea repens 

 Deschampsia flexuosa 

 Polypodium vulgare 

 Carex pennsylvanica 

 Peramium pubescens 

 Heuchera americana 

 Porteranthus trifoliatus 

 Solidago rugosa 

 Chim a pit ila macu lata 

 Asplenium platyneuron 

 Ante n n aria plan tagin ifo Ha 

 Potentilla canadensis 

 Houstonia coerulea 

 Solidago concolor. 



Outcrops of rock and rocky slopes which are kept constantly 

 moist by the seepage of underground water seem to have been 



