16 FOUNDATIONS OF BOTANY 



long, rigid, sheaths very short. Staminate catkins dull yellowish- 

 piirple, 1 in. long. Cones solitary, short-peduncled, often reflexed, 

 ellipsoid-conic, about 2 in. long ; scales thickened at the apex and 

 armed with a slender, straight, or recurved prickle. On dry, sandy 

 soil ; ■wood light, soft, weak, and of little value.* 



5. P. sylvestris, L. Scotch Pine (wrongly called Scotch Fir). A 

 medium-sized tree, with the older bark reddish and scaly. Leaves in 

 twos, 1^-2^ in. long. Cones rather small and tapering (Fig. 1, I c). 

 Cultivated from Europe. 



6. P. resinosa, Ait. Ked Pine, Norway Pine. A tall, rather 

 slender tree, with bark reddish-brown and moderately smooth. 

 Leaves in twos, slender, and 5-6 in. long. Cones borne at the ends 

 of the branches, smooth, about 2 in. long. A valuable timber tree, 

 which often grows in small, scattered clumps ; wood firm, pale red, 

 and not very resinous ; "used in house and bridge building, and for 

 masts and spars. 



7. P. palustris, Mill. Long-leaved Pine. A large tree; bark 

 thin-scaled, wood very resinous, old trees with only a few spreading 

 branches near the top. Leaves in threes, 10-15 in. long. Sheaths 

 1-1:^ in. long, crowded near the ends of very scaly twigs. Staminate 

 catkins 2-3 in. long, bright purple, conspicuous. Cones terminal, 

 ellipsoid-conical, 6-10 in. long, diameter 2-3 in. before opening, 4-6 

 in. when fully opened ; scales much thickened at the apex and armed 

 with a short recurved spine at the end. The most common tree in 

 the pine barrens ; wood hard, strong, and durable, especially valua- 

 ble for floors and inside work.* 



n. PICEA, Link. 



Sterile flowers generally axillary (sometimes terminal), borne 

 on the twigs of the preceding year. Fertile flowers terminal. 

 Fruit a nodding, thin-scaled cone, ripening in the first autumn. 

 Leaves evergreen, needle-shaped, four-angled, scattered or 

 spirally arranged. 



1. P. nigra, Link. Black Spruce. A small tree, usually only 

 20 or 30 ft. high, often less. Leaves strongly 4-angled, bluish-green, 

 and glaucous, ;J-f in. long. Cones ovoid, pointed, ^-1^ in., usually 

 about 1 in. long, persisting sometimes for 20-30 years. Wood of 

 little value except for paper-pulp. The tree is especially abundant 

 northward, and is of common occurrence in peat-bogs. 



2. P. rubra, Dietrich. Red Spruce. A large tree, 70-80 or even 

 100 or more feet high, of strict conical habit. Leaves dark green 

 or yellowish and glossy, ^— J long. Cones ovoid-oblong, acute, usually 

 lj^-2 in. long, mostly falling the first year. This is the principal 



