1909.] STRAND PLANTS OF NEW JERSEY. 83 



surface of the dune sand. The upper epidermal cells are thin- 

 walled. The palisade layer consists of one row of cells and below 

 it we find cells here and there containing a mucilaginous substance 

 in which are imbedded raphides, or needle-shaped crystals. The 

 loose parenchyma is prominent and the lower epidermal cells are 

 thin-walled and from them grow out long unicellular, sharp-pointed, 

 straight hairs which become matted together. This hairy covering 

 is of use in the regulation of transpiration. The guard cells are 

 somewhat depressed (Fig. i6a) and the leaf exhibits a typic di- 

 photophyll structure. 



Vitis (BStivalis (Plate IV, Fig. 17). — The summer grape has large 

 unlobed or more or less deeply and obtusely 3-5-lobed leaves, pro- 

 vided with a very wooly and mostly rust-red, or tawny-flocculent 

 tomentum. This tomentum does not appear in the section, because 

 the wooly hairs are mostly attached to the veins beneath and merely 

 cover the epidermal surface between, so that a section which does 

 not include the veins does not show the hairy covering of the under 

 side of the leaf. The upper and lower epidermal cells are thin- 

 walled and in the single palisade layer are found cells containing 

 a mucilage in which are imbedded raphides, or needle-shaped crys- 

 tals of calcium oxalate. 



Ilex opaca (Plate III, Fig. 3; Plate IV, Figs. 18 and i8a). — In 

 the reproduced photograph (Plate III, Fig. 3), the holly is found 

 associated with Sassafras officinale, Rhus radicans and Solidago 

 sempervirens. The leathery oval, spiny-margined holly leaves have 

 an upper epidermis of small cells covered with an extremely thick 

 cuticle. Three rows of palisade chlorenchyma are present and a 

 loose parenchyma, as an area of considerable width with large inter- 

 cellular lacunae. The lower epidermis consists of thick-walled cells 

 and the guard cells, if sunken, are only depressed to the extent of 

 the thick cuticle. Sphgerocrystals are present in some of the cells 

 of the third palisade row of cells. A tree with spineless-margined 

 leaves was formerly found on the dunes at South Atlantic City. 

 The leaf is a typic, xerophytic diphotophyll. 



Baccharis halimifolia (Plate IV, Figs. 19 and 19a). — The leaves 

 of the groundsel bush are thickish, vertical and obovate to wedge- 



