210 MISC. PUBLICATION 303, U. S. DEPT. OF AGRICULTURE 



A small to large shrub ; flowers May-August. 



Intricately branched, often many-stemmed ; occurs in clay, sand, and other 

 soils ; root system fairly deep, scarcely spreading. 



Stomach records: Columbian chipmunk, black-tailed deer. Observations: Of 

 outstanding importance as browse for mule deer ; pica, painted chipmunk, sage 

 brush chipmunk ; one of the chief browse plants for deer and antelope. 



A 'very important browse plant seldom touched by horses but extensively 

 cropped by goats, cattle, and especially sheep ; palatability appears greatest in 

 spring, winter, and late fall. 



Pyracantha coccinea, see Cotoneaster pyracanlha. 



Pyrus americana, see Sorbus americana. 



Pyrus angustifolia, see Mains angustifolia. 



Pyrus arbutifolia, see Aronia arbutifolia. 



Pyrus bracteata, see Mains Iracteata. 



Pyrus coronaria, see Mains coronaria. 



Pyrus diversifolia, see Mains fusca. 



Pyrus fusca, see Mains fusca. 



Pyrus glabrata, see Mains glabrata. 



Pyrus glaucescens, see Mains glaucescens. 



Pyrus ioensis, see Mains ioensis. 



Pyrus lancifolia, see Mains lancifolia. 



Pyrus mains, see Mains pumila. 



Pyrus melanocarpa, see Aronia melanocarpa. 



Pyrus nigra, see Aronia melanocarpa. 



Pyrus occidentalis, see Sorlus occidentalis. 



Pyrus platycarpa, see Mains platycarpa. 



Pyrus rivularis, see Mains fusca. 



Pyrus sambucifolia, see Sorftus americana. 



Pyrus sitchensis, see Sorbns americana and S. sitchensis. 



Pyrus soulardii, see Mains sonlardii. 



Quercus spp. Oaks. 



There are two classes of oaks ; the black oak group and the white oak group. 

 The acorns of the white oaks mature in a single season. Those of the black 

 oaks ordinarily take 2 years to mature. It seems possible to insure a consistent 

 crop of acorns by planting oaks of the two groups in mixtures when a con- 

 sistent food supply is assured to wildlife. Where one type may fail to produce 

 seed, the other may supplement. White and black oaks occur in about equal 

 numbers in the eastern United States and in the Mexican Sierras, Cordillera, 

 and tableland. The total number of species of white oaks in the United States 

 amounts to about 54 ; of black oaks 26, and of an intermediate class 4, making a 

 total of approximately 84 species. The timber produced by the white oaks is 

 heavier, harder and more durable than that of the black oaks. Together they 

 produce about half the hardwood lumber of the United States. 



As a class the oaks are slow growing, long-lived, disease-resistant, very little 

 subject to insect attacks. One thinks immediately of oak galls or oak apples, 

 but these malformations are seldom of sufficient importance to make much 

 difference to the general vigor and health of the species involved. 



The poisonous properties of oaks should be considered in making any exten- 

 sive plantings of them. It is known that concentrated feeding of stock on oak 

 forage may result in tannic acid poisoning. This is true especially in the 

 spring. However, cattle losses are apt to occur when other forage is scarce, 

 as in the spring, in dry years, and on overgrazed range. Proper management 

 of livestock should preclude any serious effects from the oaks. The best prac- 

 tices would include grazing cattle in summer and fall on oak, not grazing 

 them before grass has had a chance to become lush, and in general, seeing to 



