i68 ' The Botanical Gazette. [J une - 



U. latifolia 



Uniola latifolia Michx. — A series of anatomical sections 

 have been figured on plate xv. These sections have been 

 taken from the middle part of a completely developed leaf. 



As regards the structure of the epidermis of the superior 

 face (fig. i), this does not show anything of particular interest. 

 The cells of which it consists are of different size and shape, 

 forming longitudinal lines in the blade, and the differences 

 •depend upon situation. 



The large bulliform cells 9 lie in broad lines, covering the 

 green parenchyma between the large nerves, and they form 

 about six rows of rectangular, uncolored cells. Sometimes 

 and especially toward the midrib they are interrupted by 

 prominent and roundish groups of cells, surrounding the base 

 of long, stiff and pointed unicellular hairs. Bordering on each 

 side of these strips of bulliform cells there are some rows of 

 smaller, rectangular cells, the side-walls of which are more or 

 less undulated. They cover a small part of the green paren- 

 chyma. The stomata are to be observed here, and they form 

 only a single line on each side of the groups of bulliform cells, 

 while the other lines possess numerous short, very thick- 

 walled and pointed expansions. In alternation with these 

 thorn-shaped expansions are also to be seen short, unicellular, 

 slightly curved and obtuse hairs. Besides these rows of epi- 

 dermis cells there are still a few. from one to five, rows which 

 cover the stereome. These consist of very short and narrow 

 cells, the walls of which are strongly thickened. 



Comparing the epidermis of the superior face, described 

 above, with that of the inferior face, we see the following differ- 

 ences. The bulliform cells are entirely absent, as well as the 

 long hairs; the short hairs are on the contrary also to be ob- 

 served here together with the thorn-shaped expansions, which 

 are still more numerous on this face. The stomata show the 

 same distribution and number as mentioned before. 



We now examine a transverse section of the whole blade, 

 which, compared with similar sections of the other species of 

 the genus, shows differences worthy to be considered as 

 specific. Figs. 2 and 3 represent respectively sections from 

 the middle part of the blade and a small lateral part, adjoining 

 this. The me dian nerve (fig. 2) does not occupy the whole 



8 Duval-Jouve; Histotaxie des feuilles de Graminees I c. p. 310 



