Betts. — Rosette Plants at Cass. 



255 



Anatomy. 



Leaf (figs. 3-lOa). — In the leaf all the large veins, especially the midrib, 

 are prominent on the under-surface. The upper epidermis (figs. 4 and 5) 

 consists of fairly large cells, more or less oval in transverse section, which 

 have thickened walls, the outer wails being the more thickened. In surface 

 view these cells are irregular in outline. Stomata are numerous, there being 



Fig. 2. — Geum parviflorum. Plant from exposed position (half natural size). 



about 75 per square millimetre on the upper surface. The lower epidermis 

 is similar to the upper, except that the cells are somewhat flatter as seen in 

 transverse section, and as seen in surface view they are more irregular in 

 shape, the cell-walls having a wavy outline. On the lower siirface stomata 

 are more numerous, there being about 230 per square millimetre. The 

 stomata are at the same level as the epidermal cells, and the guard-cells 

 have thick walls. On both surfaces of the leaf there are hairs, which are 



