UVA-URSI 



507 



FIG. 215. Arctostaphylos Uva-Ursi. A, transverse section of part of the stem: 

 C, cells of cortex; St, peri cycle composed of sclerenchymatous fibers; L, 

 leptome; H, tracheae; Mp, a medullary ray. B, transverse section of petiole; 

 Coll, collenchyma; P, large elliptical plates of parenchyma containing chloro- 

 plasts; L, leptome; H, hadrome or woody portion of the bundle. C, trans- 

 verse section of leaf: Ed, dorsal or lower epidermis; P, loose mesophyll, the 

 cells of which, near the epidermis are palisade-like and toward the center of 

 the blade are more nearly isodiametric. D, transverse section of ventral 

 portion of midrib: Ep, epidermal cells; P, cells containing chloroplasts; 

 Coll, collenchyma; St, stereome; H, hadrome-parenchyma. E, transverse 

 section of dorsal portion of midrib: L, portion of leptome; the other letters 

 as in D. F, surface view of epidermal cells, showing the stomata and sur- 

 rounding cells, which are alike on both surfaces of the leaf blade. G, one 

 of the thin-walled glandular hairs of the stem. After Holm, Merck's Report 

 1911, p. 95. 



