The Oaks 



of the Rocky Mountains, have no indigenous oaks. No Pacific 

 coast species is distributed also in the Eastern States, and vice 

 versa. No European, Asiatic or American species is found outside 

 its own continent, except as it is introduced by man. 



The acorn distinguishes oaks from all other trees. It is the 

 characteristic fruit of the family, and is found nowhere outside of 

 it. All oaks bear acorns when they are old enough. Few begin 

 bearing under twenty years of age. 



The leaf of an oak is also characteristic. People usually 

 learn to know an oak leaf from those of other trees without realis- 

 ing exactly how or why. There is great variety in the lobing of the 

 leaves, but they are all simple, alternate and almost always oval 

 m outline, leathery, and cut by deep bays, called sinuses. 



The flowers of oaks are separate, but near together on the 

 new shoots. The staminate are in fringe-like catkins; the pis- 

 tillate few-Fowered clusters in the axils of leaves; except in the 

 genus Pasania. The acorns are either one or two years in ripening. 

 It happens that annual-fruited species have rounded lobes and 

 sinuses in their leaves. Quercus alba is the type of this class, and 

 as these trees generally have pale bark, they are known as the 

 white oak group. Biennial-fruited species have dark-coloured 

 bark and the lobes of their leaves end in angles tipped with bristly 

 points. They form the black oak group. Their type is Quercus 

 veluiina. 



I. Genus PASANIA, Orst. 



The Tan-bark or Chestnut Oak of California {Pasania den- 

 siflora, Orst.), formerly included in the ge us Quercus, is now set 

 apart as our sole representative of an Asiatic genus of trees that 

 stand half way between oaks and chestnuts. It is a handsome 

 oak, decked the year round in evergreen foliage, similar in form 

 to the chestnut. The leaves are coated, when young, with 

 yellow pubescence, which lights up the tree as if with golden 

 blossoms. 



In summer the crown of the tree shines again with gold. The 

 profuse staminate spikes stand erect with greenish pistillate flowers 

 at their bases. The latter are scaly, but the nut finally rises out 

 of a densely fringed cup, declaring itself an acorn, which takes two 

 years to mature. 



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