EUCALYPTUS 463 



Allied Drugs. The rind of the fruit of Punica Granatum, known 

 as pomegranate rind, occurs in irregularly curved yellowish-brown 

 fragments about 2 mm. in thickness. It contains 23.8 to 25 per cent 

 of a tannin which is colored bluish-black with solutions of ferric salts. 



MYRTACE^E, OR MYRTLE FAMILY 



A family of about 2000 shrubs and trees, chiefly indigenous to 

 Australia and tropical America. The plants yield a large number 

 of economic products and some, as the species of Eucalyptus, are 

 to be classed among the leading timber trees of the world. The 

 leaves are simple, the flowers are perfect, and the fruits are either 

 fleshy and berry-like, or capsular. In certain species of Eucalyp- 

 tus the leaves are both horizontal and vertical, and exhibit a dimor- 

 phic structure, the former being bifacial and the latter centric. In 

 the leaves of Eucalyptus Globulus the cuticle is thick and coated 

 with wax. Schizogenous secretory cavities are characteristic of the 

 plants of this family, and are distributed throughout the paren- 

 chyma of the stems and leaves, giving to the latter pellucid-punctate 

 areas. The secretory cavities arise very early in the development 

 of the tissues; and the secretion, which is of an oily nature, develops 

 in a resinogenous layer lining the cavity, the walls of which finally 

 become more or less suberized. Tannin cells are of quite common 

 occurrence in the parenchymatous region of the axis and leaves. 

 Stone cells are sometimes present in the primary cortex. The inner 

 bark usually consists of alternating layers of bast fibers and leptome. 

 The tracheae usually possess simple pores or scalariform thickenings, 

 except when they are in contact with the wood parenchyma, when 

 the dividing wall is marked by bordered pores. The medullary rays 

 are usually from 1 to 3 cells wide. Calcium oxalate is secreted in the 

 form of rosette aggregates and ordinary solitary crystals. The non- 

 glandular hairs are usually unicellular and glandular hairs are wanting. 



Eucalyptus. The leaves of~Eucalyptus Globulus (Fam. Myrta- 

 cese), a tree (Fig. 201), indigenous to eastern Australia and Tas- 

 mania, and cultivated in southern Europe, California and the southern 

 United States. The leaves are collected from older portions of the 

 tree and dried, the principal part of the commercial supply coming 

 from the southern part of France. 



Description. Bilateral, lanceolate, scythe-shaped, 15 to 30 cm. 

 in length, 2.5 to 5 cm. in breadth; summit acuminate; base some- 

 what unequal, acute; margin entire, revolute; surface light green, 

 glabrous, with numerous small circular, reddish-brown depressions 



