62 



BOTANY AND PHARMACOGNOSY. 



Osmunda (Fig. 37), Aspidiinn (Fig. 227), etc. This group is 

 chiefly characterized by the underground or prostrate stems, 

 known as rhizomes, the part of the plant that is seen above ground 



being the leaf. 



- -E 



Fig. 38. A, transverse section of stipe of Aspidium marginale: E, epidermis; H, 

 hypodermis of collenchymatic cells; P, parenchyma containing starch; V, fibro vascular 

 bundle; S, sieve; T, tracheae; N, endodermis surrounding each bundle. B, transverse sec- 

 tion of stipe of Osmunda Claytoniana: H, hypodermis of lignified sclerenchymatous fibers; 

 N, endodermis of large central fibrovascular bundle; Tn, tannin cells. 



