STREET TREES. 19 



The rainfall gradually increases from west to east until at about the ninety-eighth 

 meridian the conditions are more favorable for tree growth. 



The trees to be relied on are the thornless honey locust, common hackberry, black 

 locust, .green ash, ash-leaved maple, the poplars, the Chinese elm, and the A merican elm 

 if it can be watered the first few years after transplanting. The mossy-cup oak is 

 another tree worth testing in a small way, as it is native a little east of the ninety- 

 eighth meridian. The basswood and Norway maple would probably succeed if 

 supplied with plenty of water. 



Region 8. — Region 8 is the southorn part of the Great Plains. 



In addition to the deciduous trees recommended for the northern Great Plains 

 (region 7) the ^lississippi hackberry, Texas umbrella, and chinaberry may be suc- 

 cessfully grown. 



Evergreen trees that may be used in region 8 are the Texas palmetto and Parkin- 

 sonia. 



Region 9. — Region 9 is the upper ^Mississippi Valley, including the area from that 

 already considered to Lake Michigan and south to southern Kansas. It is more 

 favorable to tree growth than regions 6 and 7. 



Trees which ^^ill succeed here are the American elm; red, pin, mossy-cup, and 

 other native oaks; white ash; sycamore; basswood; and Norway and sugar maples. 



Region 10. — Region 10 includes the northeastern part of the country from eastern 

 Illinois to the Atlantic Ocean, and extends southward through the Appalachian 

 Mountains. It is most favorable for tree gi'owth. 



The best trees for street planting in region 10 are the red and pin oaks, London 

 plane, sycamore, the staminate form of the ginkgo, basswood, tulip, Norway maple, 

 white ash, thornless honey locust, American elm, and in the southern portion of the 

 region on light land the sweet gum. The red and sugar maples are among the best 

 trees for suburban conditions. The hackberry will grow, but should be discarded 

 in favor of better varieties. The mossy-cup and chestnut oaks are worthy of trial 

 on gravelly soils in the subui'bs. 



Region 11. — Region 11 includes the lower Mississippi Valley and the country east 

 of the southern Appalachian Mountains, extending from the light lands near the 

 South Atlantic and Gulf coasts to the northern limits of the distinctively southern 

 flora. 



The typical street trees of this region are the ^villow oaks (fig. 1) and water oaks, 

 the former a valuable street tree, the latter good when young but comparatively 

 short lived, with no advantages over the willow oak. Other good trees are the red, 

 Spanish, laurel, Darlington, and pin oaks, tulip, sweet gum, American elm, red and 

 Norway maples, and the ginkgo. 



Region 12. — Region 12 is the land near the coast from Wilmington, N. C, to the 

 Mexican border, exclusive of the southern part of Florida. 



Good deciduous trees for this region are the willow, laurel, Darlington, and Span- 

 ish oaks, tulip, sweet gum, sycamore, London plane, American elm, and the stami- 

 nate form of the ginkgo. The honey locust, red or scarlet maple, Norway maple, 

 and the hackbemes are not so good. 



The live oak is the characteidstic tree of region 12 (fig. 16) and is the pride of the 

 cities that have used it. Even though an evergreen, it is an excellent street tree, 

 as it is large, spreading, and open. The palmetto and palms thrive and may be 

 used for producing formal effects. The evergreen magnolia is a good broad-leaved 

 evergreen. 



Region 13. — Region 13 consists of the southern part of Florida. The deciduous 

 trees suitable for this section are the willow, Spanish, and southern red oaks; Ameri- 

 can elm; Mississippi hackbeiTy; and in the southern half of the region the 

 Poiuciana. 



Evergreen trees are better suited to region 13 than to any other portion of the 

 United States except possibly southern California. Among the best are the live and 



