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SCIENTIFIC AND APPLIED PHARMACOGNOSY 





FIG. 79. Serpentaria. A, transverse section of stem-internode showing epidermal 

 layer (Ep) with a single stoma; cells of cortex of which the outer strata are col- 

 lenchymatous, the remainder being parenchymatous and containing chloro- 

 plastids and oil; endodermis consisting of a layer of thin- walled starch-bearing 

 cells (End) ; pericycle of several layers of thick-walled sclerenchymatous fibers 

 (St). B, section of stele of stem-internode showing sclerenchymatous fibers 

 (St) ; leptome (L) ; cambium extending to the parenchymatous rays between 

 the vascular bundles (Camb); and hadrome (H) or tracheae portion of the 

 vascular bundle. C, transverse section of a swollen node showing collen- 

 chyma (C) of which the entire cortex is made up; starch-bearing endodermis 

 (End) and steromatic pericycle (P) which is very much reduced. D, trans- 

 verse section of a secondary root showing starch-bearing parenchyma cells 

 of cortex (C); endodermis (End) of thin-walled cells with distinct (Cas- 

 paryan spots and free from starch; pericambium (P)', leptome (L); hadrome 

 (H). E, epidermis with silicified cells from the upper or ventral surface 

 of the lamina of the leaf and are the cause of the small perforations seen in 

 the leaf blade when held toward the light. F, non-glandular hairs from the 

 leaf, one of which is very prominently curved forming a small hook. After 

 Holm, Merck's Report, 1907, p. 276. 



