RELATION OF LEAF STRUCTURE TO PHYSICAL FACTORS 39 



Potentilla rubricaulis: leaf 175 p.; lower epidermis 15/4,; loose 

 sponge cells. 



Potentilla pulcherrima: (like preceding). 



Potentilla minuti folia: leaf 175 /A.; lower epidermis 15/4,; cuticle 

 5 p.; chlorenchym (135 /A) 2-3 rows palisade cells 35 /*. 



Potentilla monspeliensis: cuticle 2 p.; sponge loose. 



Potentilla bipinnatifida: leaf 125 /A; epidermis 15 /A; cells 25 /A. 



Sibbaldia procumbens. 



Gravel, half gravel, mesa, etc. : light I ; available water 2.5- 

 7.5% ; temperature and humidity variable for the various locations. 



PHACELIA LYALLII: diphotophyll 250/4,; epidermis, upper 20 p., 

 lower 15/4; cuticle thin; chlorenchym (215/1.) I close row prolate 

 palisade cells 75 /A; loose irregular sponge cells. (Plate IV, fig. 4.) 



Phacelia heterophylla: closer sponge. 



Phacelia glandulosa: leaf 225 p.. 



Pulsatilla hirsutissima (sub-type): leaf 300/4,; epidermis upper 

 35/4,, lower 30/1; cuticle thin; chlorenchym (235/4.) I close regular 

 row prolate palisade cells 100 /A ; close subglobose sponge cells. 



Pedicularis procera (sub-type): leaf 250/4,; epidermis, upper 

 30 (i, lower 20 p. ; cuticle 2 p. ; papillae on lower surface, chlorenchym 

 (200/4.) i close row prolate palisade cells 100/4,; loose irregular 

 sponge cells. (Plate IV, fig. 5.) 



HEUCHERA PARVIFOLIA: diphotophyll 250/4,; epidermis, upper 

 25 /A, lower 20/4,; cuticle 5/4,; chlorenchym (205/4.) 2-4 close rows 

 prolate palisade cells 25-40/4,; loose subglobose sponge cells. 

 (Plate IV, fig. 6.) 



Heuchera hallii: epidermis 25 /A ; cells close. 



MIRABILIS OXYBAPHOIDES : diphotophyll 475 /A ; epidermis, upper 

 35/4., lower 25/4,; cuticle thin; chlorenchym (415/4.) i compact row 

 prolate palisade cells 175/4.; loose irregular sponge cells. 



GENTIANA AFFINIS : diphotophyll 350 p. ; epidermis, upper 35 /A, 

 lower 30/1.; cuticle 5/4.; chlorenchym (285/4.) 2 close irregular rows 

 prolate palisade cells 75 p.; loose irregular sponge cells. (Plate IV, 

 %. 8.) 



Coleanthus congestum: leaf 300/4.; epidermis, upper 25/4,, lower 

 15 /<, ; cuticle 2 p. ; closer sponge. 



Kuhnia gooddingii: leaf 300 /A; epidermis, upper 20 p., lower 15 p- ', 

 palisade cells 60/4,. 



Senecio eremophilus ( sub- type ): leaf 350/4; epidermis, upper 



