60 Sfcflf — ^[ilditioiis to the I'lord of lV(ts/ii/i(/(o)t. 



904. Habenaria lacera (Michx.) K. Br. 



One or two specimens on high ground, Cabin John. A larger amoinit 

 in Kenilworth swamp and in the swamji north of Beaver Dam branch. 

 Also a specimen at Magnolia Run. 



*go4a. Habenaria peramoena A. (iray. 



A single specimen at Feeder Dam. 

 910. Qyrostachys simplex (A. Gray) Kuntze. 



Connecticut Avenue Bridge, August 2G, 1897; Ardwick, September 0, 

 1897. 



915. Achroanthes unifolia (Michx.) Baf. 



Glen Echo Heights (Mrs. Steele), September ]'.',. 1S!H). in fruit. 

 917. Leptorchis Loeselii (Tj.) MacM. 



Fruiting .specimens were found in the Howard Hill reservoir, .luly 2, 

 1898, and on the Leesbiirg pike toward Great Falls, September 18, 1899. 



867. Populus grandidentata Michx. 

 Terra Cotta and Lakeland. 



868. Populus deltoides Marsh. 



Xone of the specimens I have met with are clearly native. A male 

 and female, perhaps forty feet high, stand on the flats at the iron bridge 

 over Kock Creek near Massachusetts avenue extended, and other ex- 

 amples occur on the Potomac flats. 



866. Salix purpurea B. 



One tree was found on the I'otomac flats east of railroad, April 20, 

 1900. 



^33' Quercus macrocarpa Michx. 



The only tree 1 ha\e seen stands in the woods on the bluff above the 

 canal, at the District line. 



838. Quercus prinoides AVilld. 



Specimens about two feet high, in flower, Bladensburg, May 17, 1898; 

 also banks of Rock Creek above Military road and on the adjacent ridge, 

 the last much larger. 



806. Celtis occidentalis L. 



The only specimen known to me stands by the road half a mile above 

 Cabin John. 



806a. Celtis pumila Pursh. 



The restoration of this species by Mr. E. J. Hill (Bull. Torr. Club, 27: 

 49G) is welcome. Common in the vip-river region; seen also at Marshall 

 Hall and on the Giesboro Road. Mainly on the flats but sometimes on 

 the bluffs. 



*8iio. Morus alba tatarica Sieb. it Zuce. 



A tree thus determined by Mr. Sudworth stands in the waste ground 

 below the old observatory, and the same variety occurs along the Canal 

 road. It fruits freely. 



807. Humulus lupulus \j. 



Field near Tenleytown .Junction: roadside south end of Chain Bridge; 



