HISTOLOGY OF LEUCOTHOE AXILLARIS. 4i)9 



Hypodermal collenchymatic tissue in a few layers above and below 

 the larger veins. 



Stereome in a thin ring almost or quite surrounding the larger veins, 

 that on the leptome side separated from the collenchymatic tissue by 

 several layers of colorless x>arenchyma. 



Leucothoe axillaris (Lam.) D. Don. 1 



Hygrophile Forest formation. 



Leaf thick, evergreen, bifacial, dark and shining above, pale 

 beneath. 



Epidermis: Cells alike on both faces, large; their radial walls 

 slightly undulate; outer wall and cuticle strongly thickened; cuticle 

 slightly wrinkled. Stomata (fig. 89) large, mostly parallel to the 

 veins but, with many exceptions, slightly 

 prominent; guard cells with thick, strongly 

 wrinkled cuticle; each stoma bordered by 

 usually four epidermal cells, two of which 

 are parallel to and in all respects resemble 

 the guard cells. Hairs scattered along the 

 impressed midvein on the upper surface of 

 the leaf, nearly erect, very thick-walled, 

 sharp-pointed, unicellular (much as in spe- 

 cies of Ilex). 



. 7 .. Fkj. s'.». Ijeuvothoe axillaris. 



Palisade two-layered, compact. PneU- Lower surface of leaf showing 



matic tissue very open, with numerous, stomata. Magnified 480 timus. 

 rather large, intercellular spaces. Scat- 

 tered cells of the mesophyll contain sharp-pointed masses of calcium 

 oxalate crystals. 



Hypodermal collenchymatic tissue in two or three layers above and 

 beneath the larger veins — that above adjoining stereome, that beneath 

 separated from the mestomatic stereome by very open pneumatic tis- 

 sue, which contains crystals. 



Stereome in two strong groups adjoining, respectively, the hadrome 

 and the leptome of the larger veins; also in strong groups in the leaf 



1 Vesque (Ann. Se. Nat. Bot, ser. 7, vol. 1, p. 233) observes that "apart from 

 some rare species the Ericaceae are eminently xerophile." The truth of this 

 statement is borne out by the structure of those species which occur in the Dismal 

 Swamp, where, if anywhere, hygrophile species would be sought. 



Compare Niedenzu in Engler's Bot. Jahrb. , vol. 11, p. 185 (1S!>U). L. axillaris 

 anil L. cateabaei are there characterized and the glandular hairs of both species 

 are figured (t. <>'./. 1<>). Although Niedenzu says ''the glandular hairs persist 

 on the old leaf/' I could find none on my material of either species. Nor did my 

 specimens of L. axillaris show more than two layers of palisade, while Niedenzu 

 gives 3 or 4 as their number. He found 4 to 6 subsidiary cells about the stomata 

 in this group of species. 



