492 BOTANICAL SURVEY OF DISMAL SWAMP REGION. 



on the dorsal, the walls thin (even the outer only slightly thickened), 

 radial not undulate. Stomata confined to the dorsal surface, lying in 

 all directions, slightly prominent, each bordered by five to eight, 

 (mostly six) undifferentiated epidermis cells. Hairs along the veins, 

 slender, flexuous, pointed, with very thick, smooth cuticle, unicellu- 

 lar, eacli bordered by several small radially arranged foot cells. 



Hypodermal collenchyma strongly developed above and below the 

 larger veins. 



Malus angustifolia (Ait.) Michx. 



(Pyrus angustifolia Ait.) 



Ilygrophile and Mixed Forest formations. 



Leaf thin, bifacial. 



Epidermis: Cells alike on both surfaces, radial cell walls not undu- 

 late 1 ; cuticle considerably thickened, strongly wrinkled. Stomata 

 confined to the dorsal surface, lying in all directions, level with the 

 surface, each bordered by four or five ordinary epidermis cells. 1 lairs 

 none. 



Palisade in two layers of rather low cells. Pneumatic tissue open, 

 with large! intercellular spaces. 



Hypodermal collenclajma strongly developed above the large veins 

 and much more so below them, thick-walled. 



Ilex glabra (L.) A. Gray. 



Mixed and Hygrophile Forest formations. 



Leaf thick, persistent., bifacial. 



Epidermis: Ventral, cells small, almost isodiametric, radial walls 

 slightly undulate; cuticle much thickened. Dorsal^ radial cell walls 

 not undulate; cuticle and cellulose layer of the outer walls beneath 

 the midvein nearly twice as thick as elsewhere and about equaling the 

 lumen of the cells in height. Stomata confined to the dorsal surface, 

 bordered byfour or five ordinary epidermis cells. Hairs on the upper 

 surface only, scattered along the midvein (as in /. opaca and 1. vomi- 

 toria, but less pointed and with thinner cuticle), erect, prickle-like, 

 thick* walled, unicellular. 1 



Palisade compact, four-layered, the cells only slightly higher than 

 wide, all but about, one layer replaced by collenchymatic tissue above 

 the midvein. Pneumatic tissue open, with large intercellular spaces. 



Hypodermal collenchymatic tissue in about- four layers beneath the 

 midvein, with an equal number of layers beneath the thin stratum of 

 chlorenchyma above the vein. 



Stereo me very thick- walled, in a large slightly curved group adjoin- 



1 According to Solereder (Syst. Anat.,p. 237) "hairsare rare in Ilicaceae." Tn- 

 chomes of the type here described are known to him only on the petiole of Hex 

 aquifoliuvi and the blade of /. paeudothea. For a description of similar hairs in 

 Ilex vomitoria see Kearney, Contr. U. S. Nat. Herb., vol. 5, p. 29C. 



