32 EDITH SCHWARTZ CLEMENTS 



surface found in the large-celled lacunose sponge. The region of 

 small closer sponge cells doubtless represents the transformation of 

 ancestral palisade cells into sponge cells, since the saxifrages are. 

 typically sun-plants. 



MESOPHYTIC TYPES 

 SCIOPHYTA (SHADE PLANTS) 



Subalpine brook banks : light 0.03 ; available water 25-30% ; 

 humidity 60-85%; temperature 47-69. 



LIMNORCHIS STRICTA: spongophyll 350/4; epidermis, upper 125/4, 

 lower 50/4, both somewhat wavy; cuticle 2/4; chlorenchym (175/1) 

 irregular sponge-like cells loosely arranged throughout the leaf, but 

 more closely in the upper part than in the lower. (Plate II, fig. 2.) 



VAGNERA LEPTOSEPALA: diphotophyll 150/4; epidermis, upper 

 30/1, lower 20 /i ; cuticle 2/1; chlorenchym (100/1) I row globose to 

 oblate palisade cells 25/1; loose oblate sponge cells. (Plate II, 



%. 30 



Streptopus amplexifolius: upper epidermis 60/1; upper cuticle 

 3 /A ; surfaces slightly undulating. 



EPILOBIUM ADENOCAULON: diphotophyll IOO/A; epidermis 15/4; 

 cuticle thin ; chlorenchym (70/1) I row of funnel and subglobose 

 palisade cells 25/1; loose oblate to globose sponge cells. (Plate 

 II, fig. 4.) 



Washingtonia obtusa: leaf 75/4; epidermis wavy. 



Asplenium filix-foemina: upper epidermis 20/4. 



Alpine rock-clefts: light 0.05; available water 12-17%; hu- 

 midity 40-60% ; temperature 3O-55. 



SAXIFRAGA DEBILIS : diphotophyll 270 /A ; epidermis upper 25 /A, 

 lower 20/4; cuticle thin; chlorenchym (225 /t) i lacunose row prolate 

 palisade cells 75 /i, and a shorter row of subglobose cells ; lacunose 

 oblate sponge cells. (Plate II, fig. 5.) 



Senecio carthamioides: leaf 325 /A. 



CICUTA GRAYII : diphotophyll 275 /t ; epidermis 30 /A ; cuticle thin ; 

 chlorenchym (215/4) 1-2 lacunose rows prolate palisade cells 75 /A, 

 the lower row where present, shorter and more indefinite ; lacunose 

 oblate sponge cells. (Plate II, fig. 6.) 



Spruce forests: light 0.03; available water 12-16%; humidity 

 40-70% ; temperature 48-72. 



