358 



ARBORICULTURE 



ARBORICULTURE 



tree, suitable for narrow streets in the heart of a 

 large city. 



Quercus alba (white oak). A most picturesque tree, 

 attaining the largest size. The gem of American trees, 

 and not so slow-growing as usually considered. Dead 

 leaves hang on most of the winter. Figs. 313, 322. 



Quercus bicolor (swamp white oak) . A large, handsome 

 oak of moderately rapid growth, suited to moist situa- 

 tions. It seems to succeed under city conditions. A 

 desirable shade tree, almost as handsome as the white 

 oak and a little faster grower. 



Quercus coccinea (scarlet oak). Comparable to the 

 red oak but not quite so sturdy and vigorous under all 

 conditions, but with a little more brilliant autumn 

 coloring and leaves more finely cut. 



Quercus laurifolia (laurel oak, water oak). The stand- 

 ard street tree for the South. A large, handsome, 

 deciduous tree, not so desirable as the live oak, but of 

 more rapid growth. 



Quercus Michauxii (cow oak). A good oak for thin 

 gravelly lands. Not so desirable as the other oaks on 



318. Spanish Fir. Abies Pinsapo, showing the verdure 

 from top to base. 



good ground and not adapted to the extreme northern 

 sections. 



Quercus macrocarpa (mossy-cup oak). A handsome 

 and satisfactory tree, not so large as some of the others. 

 One of the most promising for the plains. 



Quercus nigra (possum oak, water oak). Another 

 good oak south of Norfolk. A little more upright in 

 growth than Q. laurifolia, but not quite so desirable 

 except possibly in its more northern limits. 



Quercus paluslris (pin oak). A quick-growing, good- 

 sized tree, with pendulous branches when old. Hand- 

 some cut leaves, brilliant in autumn. One of the best. 

 Its pendulous branches may sometimes be a rather 

 serious objection. Dead leaves hang on well into the 

 winter. Fig. 323. 



Quercus phellos (willow oak). A large, handsome tree, 

 moderately fast-growing, satisfactory south of Wash- 

 ington in regions in which it is not attacked by a 

 growth resembling "witches' broom" of the celtis. 



Quercus rubra (red oak). Almost the best street tree. 

 Large, symmetrical, rapid in growth, fine autumn foli- 

 age, head not too dense. It is exceeded only by the 

 elm in rapidity of growth among the trees suited for 

 street planting and not by that in the southern half of 

 the country. 



Quercus virginiana (live oak). A large evergreen. The 

 best street tree for the South, but slower in growth than 

 Q. laurifolia. 



Sterculia platanifolia (varnish tree). A small tree of 

 reasonably rapid growth bearing bright yellow flowers. 



It has a tropical suggestion. Good only for the South 

 and its principal value is in its possibilities for the 

 Southwest, especially semi-arid Texas. 



Tilia americana (basswood, American linden). A 

 large, handsome, quick-growing tree. Young trees are 

 sometimes affected by a disease at the base of the trunk, 

 but the tree is well worth growing except in regions 

 in which the difficulty is known to be present. 



Ulmus americana (elm, white elm). The shade tree of 

 New England and deservedly ranked first there. It 

 loses its preeminence as one goes from New England, but 

 a large, quick-growing tree worth using except in the 

 extreme South. Drops its foliage too early to be the 

 ideal shade tree in the middle states and southward. 

 It is subject to the attacks of the elm-leaf beetle in 

 regions in which that has been introduced. 



F. L. MULFORD. 



The conifers in particular. 



The cone-bearing trees (Pinacex and allies) are 

 decidedly the most important order of forest trees in 

 the economy of civilized man. They have furnished the 

 bulk of the material of which our civilization is built. 

 The remarkable combination of strength and stiffness 

 with the smallest weight compatible, and the abundance 

 and gregariousness of their occurrence, give them this 

 important position. 



From the standpoint of the horticulturist, the coni- 

 fers also take a prominent place among the materials 

 for landscape gardening effects, and, in the more practi- 

 cal use, as windbreaks. Their evergreen habit for all 

 except the larch and ginkgo tribes are evergreen and 

 their conical form, especially in earlier periods of life, 

 with a branch system persisting to the base for a long 

 tune, are the elements that make them desirable. 

 To these graces may be added the peculiar form and 

 striking coloring of their foliage, which, in combination 

 with deciduous trees or in clumps by themselves, or in 

 single specimens, offer striking effects. 



There are two types of natural or native beauty in the 

 conifers the symmetrical and verdurous beauty of the 

 young specimen (Figs. 318, 319), and the picturesque 

 and rugged beauty of the old and timeworn tree (Figs. 

 315-317). Aside from these, there are also odd, gro- 

 tesque and formal cultivated varieties, as typified in 

 the weeping spruce (Fig. 320), the columnar junipers, 

 and the various dwarf pines and spruces. 



The majority of the species belonging to this group, 

 as well as their greatest numerical development, is 

 found in the temperate zones, only a few belonging to 

 subtropical or tropical countries, among which are the 

 araucarias, from South America; the dammara, dac- 

 rydium, and phyllocladus, from Australia, and neigh- 

 borhood. 



Kinds and adaptations. 



The order Coniferae comprises nearly 40 genera, and 

 about 300 species. Our own native flora, with 15 genera 

 and not less than 100 species and subspecies, is among 

 the richest, the bulk of these being found on the Pacific 

 coast. The Altantic side offers 28 species, representing 

 the genus Pinus with 12 species out of 39; 1 Larix out 

 of 3; 3 Piceas out of 7; 2 Tsugas out of 5; 2 Abies out 

 of 12; 1 Taxodium; 1 Thuja out of 2; 1 Chama:cyparis 

 out of 3; 3 Juniperus out of 11 ; 1 Tumion (Torreya) out 

 of 2; 1 arborescent Taxus out of 2: being without repre- 

 sentatives of the genus Pseudotsuga, Sequoia, Libc- 

 cedrus, and Cupressus. There are to be added a large 

 number (not less than 400) of nurserymen's varieties, 

 some of which have been enumerated in Bulletin 17 of 

 the Division of Forestry, United States Department 

 of Agriculture. 



There are also a number of exotic conifers that 

 promise satisfactory results if used in suitable locali- 

 ties, climate and soil. The Norway spruce (Picea ex- 



