158 THE PLANT LIFE OF MARYLAND 



ment. The same may be said of Sweet Gum, Black Gum, Chest- 

 nut and Hickory. Forming a second zone underneath the tall trees 

 are often to be seen the Dogwood, the Holly, the Laurel, and in the 

 more open spaces the Red Cedar, the Persimmon, the Sassafras and 

 Sumac. A third zone is usually formed by ericaceous shrubs such 

 as Gaylussacia resinosa, Vaccinium sp., Pieris mariana, Azalea nudi- 

 flora. The herbaceous vegetation is of a somewhat xeropbytic type, 

 and includes: 



Lycopodium obscurum 

 Lycopodium complanatum 

 Pteris aquilina 

 Dryopteris achrostichoides 

 Cypripedium acaule 

 Peramium pubescens 

 Ilypoxis hirsuta 

 Sarothra gentianoides 

 Baptisia tinctoria 

 Cracca virginiana 

 Meibomia sp. 

 Epigaea repens 

 i 'himaphila maculata 

 ( 'himaphila umbellata 

 Mitchell a repens 

 Gerardia purpurea 

 Melampyrum lineare 

 Cunila originoides 

 Sericocarpus asteroides 

 < 'In -ijsops is mat ian a 

 Aster ericoides 

 Coreopsis verticillaia. 



Oak-Hickory Association. — Forests in which oaks and hickories 

 predominate occur in the more mesophytic areas of the uplands, 

 especially on the soil known as Collington sandy loam, in the "For- 

 est of Prince George." Pines, oaks and hickories sometimes all 

 occur together, but this seems to represent a temporary condition, for 



