HISTOLOGY OF SYMPLOCOS TINOTOEIA. 503 



face except beneath the larger veins. Stomata large, confined to the 

 dorsal surface, lying in all directions, level with the surface, each 

 bordered by four epidermal cells, of which two are subsidiary (paral- 

 lel to the guard cells but not otherwise differentiated). Hairs only 

 on the dorsal surface, scattered along the veins, long, pericellular, 

 gland ular, with large heads. 



Palisade in one compact layer, the cells high. Pneumatic tissue 

 with rather small intercellular spaces. 



Stereome rather strongly developed next both the hadrome and the 

 leptome of the larger veins, interrupted by thin-walled tannin (?) 

 cells. 



Subepidermal, thick-walled colorless parenchyma between stereome 

 and epidermis, very little above the veins, in considerable quantity 

 below. 



Hypodermal colle-nchymatic tissue in about two layers in the margins. 



Oxycoccus macrocakpus (Ait.) Pers. 



In brackish meadows. 



Leaf small, thick ish, persistent, bifacial, dark green above, glau- 

 cous beneath. 



Epidermis: Veulnd, cells small, radial walls strongly undulate, 

 zither thin; cuticle moderately thickened. Dorsal, cells with less 

 undulate walls; 1 cuticle covered with a finely roughened coating of 

 wax. Stomata confined to the lower surface, very numerous, small, 

 lying mostly parallel to the leaf axis but with many exceptions, level 

 with the surface, each bordered by four epidermis cells, two of them 

 subsidiary. Hairs none on the surface of the leaf; small multicel- 

 lular, clavate glandular hairs sparsely scattered along the margins. 



Palisade in one layer of short cells, which are little longer than 

 wide. Pneumatic tissue open, with large lacunes. Tabular crystals, 

 probably of calcium oxalate, in the mesophyll. 



Hypodermal coUenchymatic tissue in small quantity above and 

 below the midvein. 



Stereome in massive groups of very thick-walled cells above and 

 below (adjoining) the mestome of the midvein, but only below the 

 smaller veins, which are embedded in the mesophyll. 



Symplogos tinctokia (L.) L.'IIer. 



Mixed Forest formation, usually in low woods. 



Leaf rather large, nearly horizontal, bifacial, rather thin, lateral 

 veins prominent beneath. 2 



1 This stronger undulation of the radial walls on the upper leaf surface appears 

 somewhat anomalous. 



- Sohreder, Syst. Anat. der Dicot., p. ")87, describes the lateral veins of S. adeno- 

 phylla as embedded in the mesophyll. 



23592— No. 6—01 13 



