502 BOTANICAL SURVEY OK DISMAL SWAMP KEGIOB. 



Kalmia anqustifolia L. 



Ilygrophile Forest formation. 



Leaf persistent, coriaceous, bifacial, dark green above, glaucous 

 beneath. 



Epidermis: Ventral, cells small, their radial walls somewhat undu- 

 late; cuticle greatly thickened. Dorsal, cells much smaller, their 

 lumen in old leaves hardly wider than the thickness of the cuticle; 

 cuticle bearing a deposit of wax. Stomata nunc on the ventral sur- 

 face, numerous on the dorsal surface, small, lying in all directions, 

 bordered by several undifferentiated cells of the epidermis, the guard 

 cells not projecting. 1 Hairs of two types, the first short, straight, or 

 curved, conical, pointed, unicellular, with very thick, smooth cuticle 

 and lumen almost obliterated. These form a dense covering on the 

 under surface of the young leaf, where many persist, while on the 

 upper surface they soon become broken off, forthe most part. 2 Second, 

 much fewer and larger, long-stalked, capitate, multicellular, glandu- 

 lar hairs. 



Palisade, in two or three layers of high, narrow cells, only the outer- 

 most compact. Pneumatic tissue with numerous lacunes, its cells 

 much like those of the palisade. Cells which contain rather large and 

 unusually perfect masses of crystals (" Drusen" or " macles") of cal- 

 cium oxalate are numerous in the mesophyll. 



Hypodermal coUenchymatic tissue in three layers above and below 

 the midvein. 



Stereome in a thin band of thick-walled (tells adjoining the under 

 side of the mestome bundle-group of the midvein. Also, in well- 

 developed leaves, a small group of thinner-walled stereome adjoining 

 the upper side of the vein. Finally, a small group of thin-walled 

 stereome in the slightly incurved leaf margins. 



Batodendron arboreum (Marsh.) Nutt. :i 

 (Vaccinium arboreum Marsh.) 



Mixed Forest formation, growing in dry, open woods. 



Leaf flat, horizontal, bifacial, veins rather prominent beneath. 



Epidermis: Cells low and small, with thin, undulate radial walls, 

 outer wall and cuticle considerably thickened; cuticle wrinkled, espe- 

 cially opposite the larger veins; somewhat, thinner on the dorsal sur- 



1 In many Rhododondroideae which have the under side of the leaf provided 

 with a hairy covering, tho guard cells are very prominent. Breitfeld in Engler, 

 Bot. Jahrh.. vol. 9. pp. 327-329. 



'' They arc the ' ' poils tecteurs unicellules " of Vesque (Ann. Sc. Nat. Bot. , ser. 7, 

 vol. I, p. 226), who distinguishes three types of hairs in Ericaceae. He remarks 

 that those of Kalmia are noteworthy as being narrower than the epidermis cells 

 from which they originate— a " particularity trrs caracteristique." 



:1 Compare Niedenzn in Eugler's Bot. Jahrh.. vol. 11, pp. 1!)3. 105 (18!)<>). The two 

 subsidiary cells about the guard cells of the stomata are characteristic of the 

 Vacciniaceae (loc. cit., p. 1013). 



