584 harper: phytogeography of southern Maryland 



many places with fragments of ferruginous sandstone. The 

 topography varies from flat terraces near sea level to steep hills 

 rising some 350 feet higher. Streams are numerous, but the 

 smaller ones on the more clayey soils are intermittent. The 

 gravelly bogs recently described by McAtee in his Natural 

 History of the District of Columbia^ are almost confined to this 

 region. 



About 40 per cent of the area is still wooded, in spite of its 

 proximity to two large cities, and there was a movement about 

 five years ago looking toward the establishment of a national 

 forest between Baltimore and Washington. 



The commonest trees seem to be: 



E *Pinus virginiana. Scrub pine. Quercus falcata. Red oak (southern). 



Qitei'cus alba. White oak. Nyssa sylvatica. Sour gum. 



Acer rubrvm. Red maple. Quercus marylandica. Bhxck-jack oak. 



E *Pinus rigida. Pitch pine. Quercus palustris. Pin oak. 



'^'Quercus velutina. Black oak. Platanus occidentalis. Sycamore. 



Castanea dentata. Chestnut. Quercus coccinea. Scarlet oak. 



Liriodendron hilipifera. Poplar. Quercus stellata. Post oak. 



*Quercus montana. Chestnut oak. E Pinus echinata. Short-leaf pine. 



Betula nigra. Birch. Hicoria alba. Hickory. 



Liqvidambar styraciflua. Sweet gum. Quercus phellos. Willow oak. 



Fagus grandifolia. Beech. Hicoria glabral Hickory. 



Evergreens make up about 35 per cent of the forest, and oaks 

 a little less. The undergrowth consists very largely of shrubs 

 belonging to the Ericales, of which Gaylussacia haccata (huckle- 

 berry) is probably the commonest. Epigaea (arbutus) is very 

 common, and apparently in no immediate danger of extermina- 

 tion. 



2, THE GREENSAND BELT 



This is determined by the outcrop of several Upper Cretaceous 

 and Eocene formations which consist largely of greensand marl. 

 It lies immediately southeast of the belt just described and is of 

 about the saine width. The boundary between them is pretty 

 sharply defined in some places, e.g., near Brightseat. It is 

 mostly north of the Chesapeake Beach Railway, and is best 



' Bull. Biol. Soc. Wash. 1: 74-90. :\Iay, 1918. 



