98 THE BROAD-SCLEROPHYLL VEGETATION OF CALIFORNIA. 



measurements were made of thickness of leaf and of upper and lower 

 cuticle in each species (table 13). For the sake of comparison, a 

 group of two sclerophyll species of the redwood-forest undergrowth 

 and one of 5 native deciduous trees have been added. The figures 

 given in the table are averages of 10 measurements, made in nearly 



Table 13. — Thickness of leaf and cuticle. 



Broad-sclerophyll forest: 



Myrica californica 



Castanopsis chrysophylla 



Quercus agrifolia 



Q. chrysolepis 



Pasania densiflora 



Umbellularia californica 



Arbutus menziesii 



Climax chaparral: 



Quercus durata 



Berberis pinnata 



Dendromecon rigidum 



Heteromeles arbutifolia 



Adenostoma fasciculatum 



Prunus ilicifolia 



Xylothermia montana 



Rhamnus californica 



R. crocea 



Ceanothus cuneatus 



C. papillosus 



C. rigidus 



C. sorediatus 



Garrya elliptica 



Arctostaphylos hookeri 



A. pumila 



A. tomentosa 



A. vestita 



Eriodictyon californicum 



Redwood-forest undergrowth : 



Gaultheria shallon 



Vaccinium ovatum 



Deciduous species: 



Salix lasiolepis 



Alnus rhombifolia 



Quercus lobata 



Platanus racemosa 



Acer macrophyllum 



Summaiy: 



1. Broad-sclerophyll forest 



2. Climax chaparral 



3. Average of classes 1 and 2. . . 



4. Redwood-forest undergrowth. 



5. Deciduous species 



Leaf. 



microns. 

 80 

 254 

 314 

 219 

 217 

 208 

 264 



205 

 178 

 371 

 339 

 562 

 345 

 385 

 265 

 246 

 462 

 214 

 472 

 224 

 365 

 398 

 362 

 355 

 264 

 345 



432 

 365 



111 



111 

 160 

 149 

 106 



222 

 336 

 314 

 398 

 127 



Upper 

 cuticle. 



microns. 

 3.08 

 2.63 

 3.75 

 3.75 

 2.85 

 5.58 

 2.96 



2.94 

 3.82 

 4.20 



11.58 

 9.73 

 3.98 

 5.85 

 8.25 

 5.28 

 4.65 

 2.25 

 6.86 

 1.12 



17.25 



11.82 

 8.85 

 9.89 



12.10 

 1.24 



05 



.57 



35 

 12 

 06 

 21 

 16 



3.52 

 6.36 

 5.69 

 4.31 



1.58 



Lower 



cuticle. 



microns. 

 1.84 

 1.39 

 1.80 

 2.59 

 2.06 

 3.78 

 1.80 



3.21 



2.81 

 2.67 

 7.57 

 9.66 



2.81 



68 

 49 

 17 

 96 

 08 

 50 

 12 

 52 



11.63 



5.77 



11.32 



11.44 



1.05 



2.51 

 1.61 



6.37 



7.50 



12.75 



12.00 



6.75 



2.04 

 5.23 

 4.43 

 2.06 

 .91 



every case upon 10 separate leaves, except in Adenostoma fasci- 

 culatum, Arctostaphylos tomentosa, and Quercus durata, where the 

 averages are of 40 to 50 separate leaves. 



The following order has been determined upon in the descriptions : 

 (1) general; (2) mesophyll; (3) epiderm; (4) stomata; (5) special 

 features. 



