RELATION OF LEAF STRUCTURE TO PHYSICAL FACTORS 79 



Allionia linearis 



GRAVEL: light i; available water 2.5-5.5%; humidity 30-65%; 

 temperature 55-76 : staurophyll 680 /*; epidermis 25^; upper 

 cuticle 3 [L, lower cuticle 5 /*, ; chlorenchym (630 p.} 5-6 irregular 

 rows prolate cells, the first row 200 /t, the second and third 125- 

 150 /*, the last two or three rows 50-100/1,, the first three rows com- 

 pact, the rest looser and oblobate. (Plate IX, fig. 2 a.) 



FOOTHILL THICKET (tall, flowering form) : light 0.0125 ; available 

 water 11% ; humidity 38-80% ; temperature 53-85 : diphotophyll 

 150 p,; epidermis 15/^5 cuticle thin; chlorenchym (120 /A) i row pro- 

 late palisade cells 55 p., and a partial second row ; globose sponge 

 cells. (Plate IX, fig. 2 &.) 



Gravel C. 630 ft P. S rows, 630 ft S. o 



Thicket C. 120 ft P. i row, 55ft S. 65 M 



510 M 4 rows, 575ft (91%) +65/4 



Light i /So; water +(5.5-8.5%); humidity +(8-15%); tem- 

 perature + (o-9). 



FOOTHILL THICKET (seedling): light 0.003; other factors like 

 preceding: diphotophyll no/*; cuticle thin; chlorenchym (60 p.) I 

 row globose and funnel cells 3Oju,; globose sponge cells. (Plate 

 IX, fig. 2 c.) 



Gravel C 630 ft P. 5 rows, 630 ft S. o 



Thicket C. lobft P. i row, 30 ft S. 30 ft 



470ft 4 rows, 600 ft (95%) +30 ft 



Light 1/300; water +(5.5-8.5%); humidity +(8-15%); tem- 

 perature + (o-9). 



Tall form C. 120 ft P. i row, 55 ft S. 65 ft 



Seedling C. 60 ft P. i row, 30 ft S. 30 ft 



6oft 25ft (45%) 35ft (54%) 



Light \ ; other factors the same. 



Solatium triflorum 



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

 65%; temperature 5i-76: staurophyll 375 /A; epidermis, upper 

 35 /x, lower 2O/*; cuticle 3/t; chlorenchym (325 /*) 4 compact rows 

 prolate cells, first row 125 p,, second and third rows 75-100 /A, fourth 

 row 50 p. with looser oblobate cells. (Plate IX, fig. 30.) 



