168 



Botanisches Central blatt. 



Beiheft 3. 



City of San Uiego, 



Latitude 32" 43' N. 



County of San Diego, California. 



Longtitude ll?** 10' W. Elevation 26.517 Meters. 



Temperatures expressed in degrees celsius. 



The prevailing winds are from the west and being moisture 

 laden are of some importance to the Vegetation. During night and 

 earlj morning, these winds blow the sea fogs inland. As the 

 rainfall is so small, the water obtained by condensation of these 

 fogs materialiy adds to supplj on which the Vegetation depends. 

 During the Wet season the trade winds accasionallj blow with 

 considerable violence. After one of these wind storms the less 

 hardy plants appear withered and burnt. As all regions are nearly 

 equaliy exposed to action of these winds they have but little if 

 any effect on the plant distribution. 



The Formations. 



An examination of the Vegetation of Orange County shows it 

 to be distributed into seven fairly distinct formations. These we 

 may designate as; — Mountain, Foothill, Canon, River Bed, Mesa» 

 Bog and Strand Formations. The last two of these and particularly 

 the Bog formation are much limited in area. 



The Mountain formation is found on those mountains, cou- 

 stituting the center or back-bone of the Sierra Santa Ana. These 

 are commonly over 500 meters high. The Foothill formation is 

 found on the hüls which constitute the flanks of the Sierra Santa 

 Ana and on the hills of the Laguna chain. These hüls are 

 between 300 and 500 meters in height. The Cafion formation 

 comprises plant growth on the floor and lower parts of the walls 

 of the Canons. The Vegetation found in the beds of the river» 

 and on the Mesa constitute the River Bed and Mesa formations 

 respectively. The Bog formation comprises the Vegetation growing 

 in places where the water collects to form stagnant pools. These 

 Spots are small and scattered over the Mesa at wide intervals. In 

 the southern half of the county the shore chain of hills runs down 

 abruptly into the sea, so that here flat sandy beach is only found 

 in Spots at the cafion mouths. In the northern half of the county, 

 there is a narrow strip of sandy beach between the hills and the 

 sea. The Vegetation of these Stretches of sandy beach constitute. 

 the Strand formation. 



Mountain Formation: The Vegetation of this formation 

 consists primarily of shrubs, with a minor, but constant admixture 

 of herbaceous forms. With a few exceptions, arboresccnt types 

 are wanting. The shrub growth is commonly between 2 and 



