170 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



ever, that the leaves at the time of the flowering of the tree or shortly 

 afterward will be found more active. 



Description. Oblong-lanceolate, from 10 to 20 cm. in length 

 and 4 to 6 cm. in breadth; summit acute and long-pointed; base 

 acute or wedge-shaped; margin coarsely serrate with ascending 

 mucronate teeth; upper or ventral surface dark yellowish-green, 

 puberulous, midrib and veins of the first order prominent, the latter 

 diverging at an angle of 50 to 60, and extending into the teeth; 

 lower or dorsal surface pale yellowish-green, with a fine cobweb-like 

 tomentum; petiole 15 to 20 mm. in length, slightly angled and with 

 a swollen base, yellowish or sometimes tinged with red; texture cori- 

 aceous, fibrous; odor slight astringent. 



Inner Structure. See Fig. 73. 



Powder. Olive-green or grayish-brown; non-glandular hairs 

 either single or peltate from 0.060 to 0.200 mm. in length, nearly 

 smooth and very thick-walled ; calcium oxalate occurs in the petioles 

 in the form of rosette aggregates from 0.010 to 0.040 mm. in diameter; 

 tannin-containing parenchyma cells colored bluish-green with solu- 

 tions of the ferric salts; tracheae, mostly close annular. Stem frag- 

 ments show long bast fibers with adjoining crystal fibers, the cells 

 of the latter each containing a monoclinic prism of calcium oxalate 

 from 0.010 to 0.025 mm. in length; and also groups of small stone 

 cells. 



Constituents. Tannic acid, 9 per cent, colored green with ferric 

 salts and not precipitated with a solution of tartar-emetic. The 

 drug also contains a mucilage which is insoluble in alcohol; and ash 

 45 per cent. 



Allied Plants. An extract used in the tanning of sole leather is 

 made from chestnut wood. The seeds of the chestnut tree are 

 edible and fresh chestnuts contain on an average 42 per cent of 

 starch and other carbohydrates; 6 per cent of protein; 5.5 per cent 

 of fixed oil; 1.3 per cent of ash; the remainder being water. The 

 testa is said to contain a bitter principle. 



The seeds of the Chinquapin (Castanea pumila), a low-growing 

 shrub of the southern United States, resemble those of C. vesca, 

 but are smaller. They contain 45 per cent of starch; 8 per cent of 

 ash, and 2.5 per cent of protein. (Kraemer, Amer. Jour. Pharm., 

 1895, p. 453.) 



URTICACE^, OR NETTLE FAMILY 



The plants are largely tropical, and include herbs, shrubs and 

 trees. There are about 1500 species, and as there are some funda- 



