TREES 



Melia Azedaraeh.Ynr xmhincul.fotmi-. is found un 

 satisfactory in tlie immediati M( iiiit\ . t tin (oast, a^ a 

 sidewalk tree it is eiceedii ii losing its 



leaves, and is also much sects 



Acacia melanoxylon is 1 from the 



Citrous belt, as a breedtr I iiiituie it is 



said to suffer quickly from tin (thctsot diouglit In 

 the moister climate of the immediate vicinity of the 

 coast, near San Francisco, however, it proves entirely 

 satisfactory. 



Populns alba, Bobhiia Pseudacacia and Ulmtis 

 racemosa are exceedingly troublesome when used as 

 sidewalk trees on narrow streets; their surface roots 

 often break the < 



. Tolerant of medium t 

 Acacia melanoxylon, 

 Ailantus glandulosa, 

 Albizzia lopbantha, 

 Casuarina eQuisetifolia, 

 Eucalyptus amygdalina, 

 var. angustifolia (appa- 

 rently the least sensi- 

 tive of the Eucalypts). 



AAA. Only 

 Acer maerophylluni. 

 Acer Negundo, var. Cali- 

 fomicum, 



or asphalt sidewalks, 

 and the suckers come 

 up in the midst of 

 lawns several yards 

 away from the parent 

 tree. 



Picus macrophyU'i 

 is another tree injuri- 

 ous to sidewalks. 



Eucalijplus Globu- 

 lus, and in fact almost 

 all species of the ge- 

 nus, are frequently 

 debarred by town ordi- 

 nance from growth 

 within CO or even 70 

 feet of a sewer, on ac- 

 count of the remarka- 

 ble length and pene- 

 trating power of their 



Paiilowi, 



imperi- 

 ob- 



ilkali (chiefly "white" salts). 

 Eucalyptus rostrata (Fit*. 



2566), 

 Eucalyptus sideroxylon, 



Phoenix dactylifera, 

 Platanus orientalis, 

 Populus Fremonti, 

 Quercus lobata, 

 Robinia Pseudacacia. 

 fairly tolerant. 



Cinnamomum Camphora, 

 Gleditschia triacanthos, 

 Ulmus spp. 

 Washingtonia filifera. 

 AAAA. Tested and 

 found unsuitable. 

 Most of those trees 

 of the humid regions, 

 e. er. , the (-astern states 

 iuid X. Kun.pe, which 



kMli s..ils. have been 

 f.aiiid to suffer and to 

 remain dwarf and 

 stunted. This is par- 

 ticularly true of Jyiri- 

 odendron Tulipifera, 

 Quercus pedunculata 

 and species of Tilia. 



Since writing the 

 above, the following 

 iidditiniKil information 



alis 



jected to 



of the somewhat un- 

 tidy appearance of the 

 persistent seed -pods, 

 which require no little 

 labor if all are to be 

 removed after flower- 

 ing. 



Grevillea robust a 

 has brittle wood and is 

 usually much broken in 

 heavy winds, but can 

 be used with satisfac- 

 tion if kept well cut 

 back. 



The species of Phoe- 

 nix and Jubiea should 

 be avoided on account 

 of their low, wide- 

 spreading habit, ex- 

 cept for avenues and 

 boulevards where there 

 is no sidewalk or where 

 there is from 20 to 30 

 feet space between 

 sidewalk and drive- 

 way. 



Ailanihus ylandu- 

 losa has a bad reputa- 

 tion on account of its 



disagreeable odor, but as this is only found in the stami- 

 nate trees, it can be avoided by planting the pistillate 

 (fruit-bearing) trees only. 



8. Trees for Alkali Soils. -There are many places in 

 those parts of the state that enjoy a IiIl-Ii temperature 

 and low rainfall, where the inii-. huil-i' of alkali salts in 

 the soil is too great for tin- ciiltn ati.ni ,,f uiost of our 

 ornamental trees, and where it i^ very important that 

 some shade-producing species be growu. 



A. Tolerant of strong "black" alkali (Sodium car- 

 bonate ) . 

 The most alkali-tolerant tree of those yet tested is 

 Kcelreuteria panictilata, a small species 15 to 30 feet 

 high, wdth feathery, pinnate leaves and ornamental 

 yellow blossoms. 



lia. liee,, lirouKht to 

 li^-ht tlir.mirli the in- 

 vestigations of Dr. R. 

 H. Loughridge of the 

 Agricultural Experi- 

 ment Station at Berke- 

 ley, and has courte- 

 ously been placed at 

 my disposal. 



Total amount of salts 



illy fo 



in the 



Ipjier tour teet of Soil 

 M «-|,i,-l, tl,e following 

 rees w.re L'l-owing, ex- 

 ii'essed ill tons per 



"'''■ Tons per acre in 

 depth of 4 feet. 

 Kcelreuteria pani- 



culata 32 



Platanus orientalis 2lX 

 Eucalyptus amyg- 

 dalina 20 



Eueal.yptus .■ingus- 



SOUTHEEN CaLI- 



FORNIA —Stiect Tjees- 

 StercuUa dnersifolia, Anstrali&n Bottle Tree, Acacta 

 Melanoxylon, Blackwood Acacia, Cinnamomum Cam 

 phora, Camphor Tree, jSVerciida aceri/bita, Australian 



"■ " ' ihiitus ><lii-.la STvamp Mahogany 



1 I I I / ilbatu, 



n Ja 



Gut,, 



but , , uu.tialis 



an 1 ' I Ims One de- 



cidu I i / lacli, vai um 



b) I I II ugh less known 



or u I / 1 I i ir a bettei street 



or sid<«ilk tin thin J- I Ik ti \ eij few conifers 

 other than those noted do well in this climate Any ex 

 tension of the above list must be made almost entirely 



