PLATE XLV. 



Lesquerella spathulata. 



Fig. 63. Small portion of midrib of leaf, as seen in longitudinal sec- 

 tion: A, spiral tracheary tracheid; B, undivided mother cell 

 of the sieve tubes, x 650. 



Palisade cells, surface view, x 650. 



Trichomes, as seen in surface view of the leaf. X H5. 



Trichome, as seen in leaf, cross section: A, cutmized portion of 

 wall of trichome; B, cellulose portion of wall of trichome; 

 C, mesophyll cells; D, tracheids. x 250. 



Stomata, as seen in surface view, x 650. 



Stoma, as seen in cross section, x 650. 



Leaf, as seen in cross section: A, upper epidermis; B, lower 

 epidermis; C, palisade tissue; D, vascular bundle, x 250. 



