FLORA OF THE DISTRICT OF COLUMBIA. 61 



1. Pinus strobus L. White pine. 

 Sparingly on high ground toward Rockville; also reported from Turkey Run, Barnes- 



ville, and Occoquan. Northern states, southward in the mountains to Ga. Also in 

 cultivation. 



Pinus excelsa Wall., the Himalayan pine, is frequently cultivated. It is a hand- 

 some tree similar to P. strobus, but with leaves 15-20 cm. long. 



2. Pinus rigida Mill. Pitch pine. 

 Sandy soil, scattered among Pinus virginiana. Eastern N. Amer. 



3. Pinus taeda L. Loblolly pine. 

 Found sparingly near our eastern limit; a few trees near Leland Station above 



Upper Marlboro; common along the Patuxent near the bay. A handsome tree, 

 characteristic of the Coastal Plain from southern N. J. to Tex. 



4. Pinus echinata Mill. Yellow pine. 

 Sparingly among Pinus virginiana in the southern counties of Maryland; west 



of Mount Vernon. Eastern U. S. (P. mitis Michx.) 



5. Pinus virginiana Mill. Scrub pine. 

 Our characteristic pine, forming forests in sandy soil. Eastern U. S. (P. inofs 



Ait.) 



6. Pinus pungens Lamb. Table-mountain pine. 

 A few trees in Rock Creek Park and on the bluffs of the Virginia shore of the Potomac 



above Cabin John. In the mountains, particularly along the ridges, from western 

 N. J. to Ga. 



Pinus sylvestris L., the Scotch fir, is common in cultivation. It is readily distin- 

 guished in its young state from Pinus virginiana by its bluish green young leaves 

 and by the absence of bloom on its branchlets, a character conspicuous in our 

 native tree. In America this tree is known under the name Scotch pine, though 

 the European vernacular name is fir, wliich is applied properly to Pinus sylvestris and 

 not to species of Ahies. 



Pinus austriaca Hoess, the Austrian pine, is extensively cultivated. It is readily 

 recognized by its stiff dark green leaves, 12-16 cm. long, which are marked by 10 or 

 11 resin ducts in the parenchyma. 



2. TSUGA Carr. 



1. Tsuga canadensis (L.) Carr. • Hemlock. 



Virginia shore of the Potomac above Cabin John; abundant at Occoquan. Northern 

 states, south to Va. 



3. TAXODITJM L. C. Rich. 



1. Taxodium distichum (L.) L. C. Rich. Bald cypress. 



Swamps and along rivers; south of Bowie; near Marshall Hall. Southern states, 

 north to N. J. 



* 4. JTJNIPERUS L. Juniper. 



1. Juniperus virginiana L. "Reo cedar. 



Common along the bluffs of the Potomac, in fields, and along roads; often planted. 

 Eastern N. Amer. 



The leaves are of 2 kinds, scalelike on the mature trees and subulate on the young 

 growth. 



Juniperus communis L,, the juniper, cultivated in this region but native farther 

 north, is distinguished by its verticillate subulate leaves, 10 mm. long or more. 



