(4) 



In this Guide the term "variety" is applied to two different types 

 of trees. The concealed distinction should, however, be borne in 

 mind. In the one case it refers to natural variations that occur in 

 the wild and which may be found in any batch of seedlings. An 

 example is the well-known Colorado Blue-Spruce. Seeds from 

 this tree will yield a mixture of green, "blue," and intermediately 

 colored trees. This is the only strictly correct application of the 

 term "variety." 



Most of the so-called varieties in the Garden, however, are not 

 true varieties. They do not occur in the wild from seedlings but 

 have originated in another way. At various times and at various 

 places, an individual plant of a wild species has produced an odd 

 type of foliage, often on only one or two branches. When this 

 occurred under the observation of gardeners, those odd twigs were 

 usually removed and rooted in sand. By careful culture those 

 cuttings grew into large plants whose entire foliage showed the 

 character of the original odd twig. Once established in this way, 

 thousands of plants have since been produced from the one 

 original without the intervention of seeds. Such plants may be 

 continuously either male or female or may have both sexes of 

 flowers on them. Taken collectively, they are properly known as 

 a "clou" rather than a "variety." The big majority of horticultural 

 "varieties" among the evergreens are really clonal variations. The 

 distinction, however, is not made in each case in this Guide. 



3. Inaccuracies may occur in the Guide where trees mentioned 

 are not to be found and, conversely, where trees found are not 

 mentioned. This cannot be avoided, for occasionally a tree dies 

 and must be removed; or, new trees are planted. Obviously, all 

 these changes cannot be accounted for. However, they are not 

 frequent and the liability of confusion from them is rather small. 

 Newly planted trees are usually young and small. Some large 

 old tree will generally serve to indicate approximately where the 

 text may have become inaccurate. 



II. TO THE TREES DESCRIBED IN THE GUIDE 



The trees described in this Guide are those which are commonly 

 spoken of as evergreens, e.g., Pines, Spruces, Hemlocks, and 



