FLORA OF THE DISTRICT OF COLUMBIA. 19 



flowering dogwood attracts attention. Spice bush is abundant and 

 easily distinguished by the fragrance of the broken twigs. 



Along the Potomac near Great Falls there are several species not 

 found farther east. One of the most conspicuous of these is Phlox 

 subulata, common on the rocks along the towpath. Other rock 

 plants are Sedum tematum, S. telephioides, and Opuntia vulgaris. 

 On the bluffs of the right bank of the Potomac the hemlock is an 

 interesting component of the forest flora. 



Another region of the Piedmont easily accessible is Rock Creek 

 Park, where plants may be observed though they may not be col- 

 lected without permission (PI. 2). The ravines and slopes harbor the 

 original flora of the region and can be reached from many roads and 

 paths. There are also several interesting valleys and wooded areas 

 within easy walking distance of the Rockville trolley line. The 

 upper valleys of Paint Branch and Northwest Branch lie in the 

 Piedmont, but they are not easily accessible except by special con- 

 veyance. 



The Coastal Plain region can be reached by any of the trolley 

 lines leading northeast, east, or south from Washington. 



Between the business part of Washington and Takoma Park, 

 which lies about at the fall line, there are several localities men- 

 tioned in Ward's Flora which have now been converted into resi- 

 dential districts, but the vicinity of Takoma Park itself still offers 

 much of interest. The trolley line to Laurel, lying in the valley of 

 Indian Creek and Eastern Branch or Anacostia River, opens up 

 line collecting grounds. There is a long swamp or series of swamps 

 on the east side of the Baltimore and Ohio Railroad from Hyatts- 

 ville to Berwyn and on to Beltsville, the section from Berwyn to 

 Beltsville being known as the Hollywood Swamp. The eastern 

 sector of our region, lying outside the District and between the 

 Baltimore trolley line and the lower Potomac, is not penetrated by 

 electric lines, but steam railways are available. The Pennsylvania 

 Railroad passes through Lanham and Bowie, the latter a station at 

 the limit of the 15-mile circle, from which a branch extends south 

 through Upper Marlboro and Brandywine to the lower part of the 

 peninsula. The Chesapeake Beach Railroad joins a trolley line at 

 the eastern corner of the District and runs to Upper Marlboro and 

 Chesapeake Beach. A trolley line goes to Anacostia and on south 

 to Congress Heights, from which point one can explore the valley 

 of Oxon Run and the lower left bank of the Eastern Branch. A line 

 of automobile busses runs from Washington to Brandywine and 

 beyond, passing through Silver Hill, from which the Suitland bog 

 may be reached, and through Camp Springs, from which one can go 

 by a good road to Upper Marlboro. 



