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 laurel oaks, evergreen magnolia, camphor, rubber, silk oak, or grevillea, and casuarina. Eucalypti are planted to some extent in Florida, but the climate is such that only on the drier grounds of the interior are they likely to succeed, and even there they are not to be compared with other excellent species of trees that may be cultivated successfully.
TREES FOR SPECIAL PURPOSES.
In the heart of a city, where the greatest difficulty is experienced in getting trees to grow, the ailanthus will probably thrive when nearly all other kinds fail. The sycamore and the London plane are also good for such places. The Carolina poplar will frequently grow under these conditions, and its use may sometimes be warranted.
For very narrow streets the Lombardy poplar is the best tree. ([fig. 14.]) Trees suitable for use within the reach of ocean spray or on sandy lands near the coast are the red oak and the red or scarlet maple south to Charleston, S. C., while the sweet gum and the live oak are equally good from Norfolk southward and along the Gulf of Mexico. The red oak, sweet gum, red maple, and eastern live oak are all grown successfully along the Pacific Ocean, while the California live oak can be used from San Francisco southward. The trees that endure the most alkali appear to be the bladder-nut tree,[3] London plane, peppermint gum,[4] blue gum,[5] the Washingtonia and other hardy fan palms, Canary Island date palm, the camphor tree, and Acacia cyclops and Acacia retinodes. Only the first two withstand severe freezing weather. The red oak and the red maple are worth testing for these conditions.
[3] Koelreuteria paniculata.
[4] Eucalyptus amygdalina Labill.
[5] Eucalyptus amygdalina angustifolia.
[DESCRIPTIONS OF STREET TREES.]
ACACIA.
The acacias, or wattles, are a large group mostly of small trees with showy yellow flowers. Although much used in California, many of them are too small to make satisfactory shade trees, and because of shallow rooting they are injurious to sidewalks. They also stump-sprout badly. They thrive in regions 2 and 3 and in restricted portions of regions 1 and 5.