FLORA OF WASHINGTON AND VICINITY. 21 



there grows Gaultheria procumhens, the wintergreen or checkerberry, 

 this being its only known locality within our limits. Half a mile further 

 up, and back upon the wooded slope, is the spot on which stand a dozen; 

 or more fine trees of the Table Mountain pine (P. pungens). Here also> 

 was first found Pycnantliemum Torreyi. 



To these there must be added a sixth section, extending from the- 

 Brightwood Eoad to the north corner of the District of Columbia, which, 

 lies near Eock Creek. For the first mile there is little of interest, the 

 cultivated land approaching the creek, and the low hills near its banks 

 being covered with a short second growth of scrub pine and blackjacks 

 But above the Claggett estate, on the right bank, and to some extent 

 on both sides, lies the largest forest within our limits. This wood be- 

 longs, I learn, to the Carroll estate, and is so designated in this cata- 

 logue. In ithavebeenfound very many most interesting plants. It was. 

 the first extensive tract found for the crowfoot {Lycopodium complana- 

 tum), and still constitutes the most reliable and abundant source known 

 of this plant. Its present fame, however, rests upon its hybrid oaks, of 

 which some most interesting forms have been found there. (See Field' 

 and Forest, October and November, 1875, p. 39. Botanical Gazette^ 

 October, 1880, p. 123.) Here also grow quite abnndantly Pyrola elliptica 

 and P. secunda, and very sparingly Microstylis opMoglossoides. It is also 

 a rich locality for many other species rare elsewhere. 



2. The Upper Potomac Region. 



The flora of the left bank of the Potomac is in many respects very 

 unlike that of any other locality within our limits. A mile above 

 Georgetown, and commencing from the recently constructed Outlet 

 Lock of the Chesapeake and Ohio Canal, there exists a broad and low 

 strip of country, formerly known by the name of Carberry Meadows, ly- 

 ing between the canal and the river, and extending to the feeder of the 

 canal, a distance of about three and a half miles. This interval is re- 

 lieved by two convenient landmarks, viz., one mile above the Outlet 

 Lock, a grist-mill and guano factory, popularly known as Eads' Mill, 

 and a mile further the celebrated Chain Bridge. Little Falls proper 

 begin a hundred yards above the bridge and extend half a mile or 

 more. The region above the bridge will therefore be designated as Lit- 

 tle Falls. The flats terminate in a remarkable knoll or small hillock of 

 very regular outline and abrupt sides, which, from the combined effect 

 of the feeder on one side and large overflows from it below, become&i 



