104 



PRACTICAL COURSE IN BOTANY 



M 



C sb. b P 



120 



M 



R 



FIGS. 120-121. Transverse and longitudinal sections of a fibrovascular bundle 

 in the stem of a sunflower. The two sections are lettered to correspond : M , pith 

 (parenchyma) ; X, xylem region ; P, phloem ; R, cortex ; s, spiral ducts ; s f , annular 

 ducts t, t, pitted ducts ; C, cambium between the phloem and xylem regions ; sb, 

 sieve tubes; b, bast ; e, bundle sheath; ic, cambium (parenchyma) cells ; k, wood fibers. 



