14 FOUNDATIONS OF BOTANY 



Scales of the cone few, without bracts. Leaves evergreen, generally 

 scale-like or awl-shaped. 



Cones dry and thin-scaled. Thuya, VII. 



Cones berry-like. Juniperus, VIII. 



I. PINUS, Tourn. 



Sterile flowers somewhat resembling inconspicuous catkins, 

 borne at the base of the young shoot of the season, each 

 flower consisting of pollen-scales in spiral groups (Fig. 1, 2). 

 Fertile flower-spikes which consist of spirally arranged carpel- 

 scales, each scale springing from the axil of a bract and bear- 

 ing at its own base two ovules (Fig. 1, 3). Fruit a cone, 

 formed of the thickened carpellary scales, ripening the second 

 autumn after the flower opens. Primary leaves, thin and 

 chaffy bud-scales, from the axils of which spring the bundles 

 of 2-5 nearly persistent, needle-like, evergreen leaves, from 

 1-15 in. long (Fig. 1). 



1. P. Strobus, L. WHITE PINE. A tall tree, 75-160 ft. high, 

 much branched and spreading when growing in open ground, but 

 often with few or no living branches below the height of 100 ft. 

 when growing in dense forests. Leaves clustered in fives, slender, 

 3-4 in. long, smooth, and pale, or with a whitish bloom. Cones 

 5-6 in. long, not stout. The wood is soft, durable, does not readily 

 warp, and is therefore very valuable for lumber. In light soil, com- 

 monest N. 



2. P. Taeda, L. LOBLOLLY PINE, OLDFIELD PINE. A large 

 tree ; bark very thick and deeply furrowed, becoming flaky with age, 

 twigs scaly. Leaves in threes, 6-10 in. long, slender, very flexible ; 

 sheaths -1 in. long. Cones solitary, oblong-conical, 3-5 in. long ; 

 scales thickened at the apex, the transverse ridge very prominent 

 and armed with a short, stout, straight, or recurved spine. Common 

 and often springing up in old fields ; trunk containing a large pro- 

 portion of sap wood ; timber of little value for outside work.* 1 



3. P. rigida, Mill. NORTHERN PITCH PINE. A stout tree, 

 30-80 ft. high, with rough scaly bark. Leaves in threes, 3-5 in. 

 long, stiff and flattened. Cones ovoid-conical, 2-3 in. long, their 



1 Descriptions followed by an asterisk are taken (more or less simplified) from 

 Professor Tracy's flora in the Southern States Edition. 



