41)0 BOTANICAL SURVEY OF DISMAL SWAMP REGION. 



LigUIDAMBAR STYRACIFLUA Ti. 



Occurs abundantly in the Mixed and the Hygrophile Forest, forma- 

 tions. 



Leaf bifacial. 



Epidermis: Cells, especially those of the dorsal face, rather small, 

 much broader than high, radial walls undulate; cuticle thin. Stomata 

 none on the ventral face, numerous on the dorsal face, lying in all 

 directions, level with the surface, each bordered by a pair of irrregu- 

 larly crescent-shaped subsidiary cells which arc smaller than the 

 other epidermis cells. Hairs in densely matted tufts in the axils of 

 the principal veins at the base of the under surface of the blade, 

 usually disappearing later on, long, flexuous, pointed, unicellular, 

 with thick, smooth cuticle. 1 



Palisade in two layers, cells of the inner layer short. Pneumatic 

 tissue moderately open. Large resin cavities in the mesophyll. 2 



Hypodermal collenchyma strongly developed above and especially 

 beneath the principal veins, six to eight layers in old leaves. 



Stereome forming an almost continuous thin sheath about the con- 

 centrically arranged mestome bundles of the large veins; in younger 

 leaves often limited to a few thin-walled cells above the mestome 

 group or altogether wanting. 



A large resin canal occupies the center of the mestome group of the 

 large veins. :i 



Itea vikcjinica L. 



Hygrophile Forest formation. 



Leaf rather thin, bifacial, midvein very prominent beneath. 



Epidermis: Ventral, cells large, their walls straight or nearly so, 

 thickish; cuticle smooth, thick, strongly thickened in the leaf margins, 

 where it constitutes the only strengthening tissue. Dorsal, cell walls 

 thinner, the radial strongly undulate. Stomata confined to the lower 

 surface, small, nearly orbicular, lying in all directions, level with the 

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

 Hairs on the upper surface along the larger veins and oti the leaf 

 margins, few, short, pointed, thick-walled, prickle-like, unicellular, 

 with smooth cuticle.'' 



1 According to Reinsch (Engler's Bot. Jarhb., vol. 11. p. 3.~>4) there are no hairs 

 on the leaf of Liquidambar. 



■-' Liquidambar ami Altingia are among the genera of Hamamelidaceae which 

 are distinguished from Hamamelis and other genera by the absence of sclerotic 

 idioblasts (Spicularzellen) in the mesophyll of their leaves. (Reinsch, loc. eit. , 

 303; Thouvenin, Ann. Sc, Nat. Bot., ser. 7, vol. 12, p. 131.) 



; 'The presence of this duct is characteristic of Litiuidambar and Altingia. 

 (Reinsch, loc. cit., p. 363; Thouvenin. loc. cit., pp. 140, til.) 



'My observation on this point does not agree with Thouvenin's. who states (loc. 

 cit., p. 133) that in Itea the guard cells are always lower than the other epidermis 

 cells. 



5 Smooth according to Thouvenin, loc cit., pp. 118, 125, 



