Quercus. 



CUPULIFERjE. 85 



A tree 24 to 39 metres in height, with a trunk 0.60 to 0.90 metre in 

 diameter (Q. Muhlenbergii), or often, especially toward the eastern and 

 western limits of its range, reduced to a low, slender shrub ( Q. prinoides ; 

 Q. Prinus, var. humilis, Marsh. ; Q. Prinus, var. Chincapin, Michx. f.) ; 

 dry hillsides and low, rich bottoms ; rare, except as a shrub, east of the 

 Alleghany Mountains ; very common in the Mississippi River basin, and 

 reaching its greatest development in southern Arkansas. 



Wood heavy, hard, very strong, close-grained, checking badly in dry- 

 ing, very durable in contact with the soil ; layers of annual growth marked 

 by rows of small open ducts ; medullary rays broad, conspicuous ; color 

 dark brown, the sap-wood much lighter ; used for cooperage, wheel-stock, 

 fencing, railway-ties, etc. 



The small acorns sweet and edible. 



262. Quercus Douglasii, Hook. & Am. 

 Mountain White Oak. Blue Oak. 



California, — from about latitude 39°, south along the western foot- 

 hills of the Sierra Nevadas below 4,000 feet elevation, and through the 

 Coast Ranges to the San Gabriel Mountains. 



A tree 18 to 24 metres in height, with a trunk 0.60 to 1.20 metres in 

 diameter ; common on the low foot-hills of the Sierras. 



Wood very hard, heavy, strong, brittle, inclined to check in drying ; 

 layers of annual growth marked by several rows of small open ducts, and 

 containing many scattered groups of smaller ducts ; medullary rays nu- 

 merous, varying greatly in width ; color dark brown, becoming nearly 

 black with exposure, the thick sap-wood light brown. 



263. Quercus oblongifolia, Torr. 

 White Oak. 



California, — foot-hills of the San Gabriel Mountains to San Diego 

 County ; foot-hills of the mountain ranges of southern Arizona and New 

 Mexico ; in northern Mexico. 



A small evergreen tree, 12 to 15 metres in height, with a trunk 0.45 to 

 0.60 metre in diameter ; the large specimens generally hollow and defective. 



Wood very heavy, hard, strong, brittle, very close-grained, checking 

 badly in drying ; layers of annual growth hardly distinguishable, contain- 

 ing few small open ducts arranged in many groups parallel to the broad 

 and very conspicuous medullary rays ; color very dark brown or almost 

 black, the thick sap-wood brown ; of little economic value except as fuel. 



264. Quercus grisea, Liebm. 

 White Oak. 



Southern Colorado, mountains of western Texas, southern New Mexico 

 and Arizona between 5,000 and 10,000 feet elevation, west to the Colorado 

 desert of California ; in northern Mexico. 



