EXERCISE 7 (Continued) 



Study a cross section of a coleus or other herbaceous stem 

 and find the water-conducting tissue, comparing thin sections 

 with stems colored as in Exercise 6. When you have accurately 

 located the water-conducting tissue, study its structure and 

 draw a few cells. Do they resemble any of the cells found in 

 the woody stems ? Is the water conducted in the wood or in 

 the pith? 



By the aid of your textbook find the pith, fibrovascular 

 bundles, cortex, epidermis. Make a diagram of the cross section 

 and label the parts. 



The wood and bark of older stems result mainly from the 

 growth of the fibrovascular bundles, but the details cannot be 

 followed out in elementary laboratory work. However, the 

 wood part of the bundle (inner part) and the bark part (outer 

 part) may be distinguished along with the line of growing cells, 

 cambium, which lies between wood and bark. 



References 



BERGEN and CALDWELL. Practical Botany, pp. 11-13, 44-53. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 11, 12, 62-68. 



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