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. O'bservations: 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 rery 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 pijracantlia. 
Pynis americana, see Sorlyus americana. 
Pyrus angustifolia, see Malus arigustifolia. 
Pyrus arbutifolia, see Aronia ardutifolia. 
Pyrus bracteata, see Malus hracteata. 
Pyrus coronaria, see Malus coronaria. 
Pyrus diversifolia, see Malus fusca. 
Pyms fusca, see Malus fusca. 
Pyrus g-labrata, see Malus glahrata. 
Pyrus glaucescens, see Malus glaucescens. 
Pyrus ioensis, see Malus ioensis. 
Pyms lancifolla, see Malus lancifolia. 
Pyrus mains, see Malus pumUa. 
Pyrus melanocarpa, see Aronia melanocarpa. 
Pyrus nigra, see Aronia melanocarpa. 
Pyrus occidentalis, see Sorttis Occident alls. 
Pyrus platycarpa, see Malus plafycarpa. 
Pyrus rivularis, see Mains fusca. 
Pyrus sambucifolia, see Sorhus americana. 
Pyrus sitchensis, see Sorhus americana and ;S^. sitcliensis. 
Pyrus soulardii, see Malus soulardii. 
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 
