RELATION OF LEAF STRUCTURE TO PHYSICAL FACTORS 53 



Senecio pudicus 



SPRUCE SHADE: light 0.03; available water 12-16%; humidity 

 40-70% ; temperature 48-72 : diphotophyll 300/4; epidermis, 35/4; 

 cuticle, upper 4/4, lower 2/4; chlorenchym (230/4) I close row pro- 

 late palisade cells 75 /*, and I irregular row 50-75 /t ; close star- 

 shaped sponge cells. 



HALF GRAVEL: light i; available water 4.5-7.5%; humidity 30- 

 65%; temperature 51 "-76: diphotophyll 385/4; cuticle, upper 5/4, 

 lower 3/4; chlorenchym (310/4) 2 compact rows prolate palisade 

 cells 75 /4, the second row also oblobate ; close irregular or star- 

 shaped sponge cells. 



Spruce C. 230 /* P. 2 rows, 135 M S. 95 ft 



Half gravel . C. 310/1 P. 2 rows, 150/4 S. i6o/* 



+ 80M +I5M (11%) +65 A* (68%) 



Light 33/1 ; water (7.5-8.5%) ; humidity (5-10%) ; tem- 

 perature + (3-4). 



Polemonium pulchellum 



SPRUCE SHADE : light 0.03 ; available water 12-16% ; humidity 

 40-60%; temperature 3O~55 : diphotophyll 150/4, lower surface 

 wavy ; epidermis wavy, upper 25 /4, lower 15/4; cuticle thin ; chlor- 

 enchym (100/4) i loose row funnel palisade cells 40/4; lacunose 

 oblate sponge cells. (Plate VI, fig. 40.) 



SPRUCE SHADE: light 0.008: diphotophyll 150/4, surfaces wavy; 

 chlorenchym (100/4) very loose row of broad funnel palisade cells 

 40 /4 ; lacunose oblate sponge cells. 



Spruce C. loo A* P. I row, 40 M S. 60 M 



Spruce C. IOOA* P. i row, 40 M S. 60 f- 



o o o~ 



Light 1/4; other factors the same. 



ALPINE GRAVEL: light i; available water 2.5-5.5%; humidity 

 40-55%; temperature 4O-65 : diphotophyll 200/4; epidermis flat, 

 25/4; cuticle 2/4; chlorenchym (150/4) 2 compact rows prolate 

 palisade cells, the first row 60 /4, the second row 50 /4, (both 100 /4) ; 

 compact globose sponge cells with indications of a layer of prolate 

 cells next to lower epidermis, which crowds and flattens normal 

 sponge cells. (Plate VI, fig. 4 &.) 



Spruce C. 100 /* P. i row, 40 M S. 60 M 



Gravel C. 150 M P. 2 rows, IOOM S. 50 / 



+ 5o/t -(-i row, +6o/* (150%) 10/4 (17%) 



