78 DESCRIPTIVE BOTANY. 



exudes from wouuds in the bark, which is the Gum Guaiac of the Materia 

 Medica. The resiu yields to the chemist HO, C12H7O5, Guaiacic Acid. 



Geography. — This tree is exclusively American ; it has a narrow geograph- 

 ical distribution, indigenous in the West India Islands, but thus far has not 

 been found upon the mainland. Another species, (i. sanctum, has been detected 

 in Florida. 



Etymology. — The name Guaiacuin is from the native name, Guaiac, which 

 undoubtedly refers to some property of the plant. Officinale signifies, of the 

 shops, referring to its sale and use. Liynum-vitie, the wood of life, is named 

 from its medicinal properties, as it is said to preserve life. 



History. — The Guaiac is a resinous substance which flows from wounds in 

 the bark, and hardens on exposure to the air and sun heat. It is friable, and 

 of a greeuish-red color. The bark aud. wood also are charged with this resin, 

 and are therefore medicinal. The leaves, fruit, and flowers are all purgative. 

 As it is an American tree its use is recent, but soon after the discovery of 

 America, in 1508, it was obtained from the natives of Haiti by Gonsalvo 

 Ferrand and taken to Europe. 



Use. — The wood is very hard, takes a fine polish, aud is so heavy and close- 

 grained as to sink in water. It is a favorite wood in the hands of the turner ; 

 it is manufactured into rulers, pulleys, ships' blocks, bearings in steam ma- 

 chinery, mortars, pestles, bowls, and vases. 



The resin is stimulant aud very diffusive in the system, and affects the skin, 

 kidneys, and the intestinal canal very actively. In large doses it is cathartic. 

 It is administered in the form of pills and tinctures 



Order XIV RUTACE^. 



Flowers inferior or perigynou.s. Sepals and petals imbricate, 4-5. 

 Stamens double the number of petals, or equal (in the citrus, numer- 

 ous and indefinite), inserted on the receptacle or a surrounding disk. 

 Leaves alternate, sprinkled with pellucid dots, containing a bitter, 

 aromatic oil. Fruit in the orange family a berry. Shrubs and small 

 trees. 



Genera, 83. Species, 450. 



CITRUS, L. Caljrs 5-sepaled. Petals 5-10, white, fleshy, fragrant. 

 Stamens numerous and some multiple of 5. Filaments flat at the 

 base and united in sets. Anthers versatile. Style 1. Ovary many- 

 celled, ripening into a pulpy berry. Shrubs and small trees. 



1. C. aurantium, L. (Sweet Orange.) Stem about 6 to 8 feet to the point 

 where the head begins to form, much branched ; branchlets armed with spines, 

 forming a symmetrical tree from 15 to 25 feet in height. Leaves ovate, tapering 

 to a point ; petiole winged ; blade leathery, dark-green above, lighter beneath, 

 evergreen, articulated to the petiole. Flower white, with a very delicate, fra- 

 grant odor. Fruit a berry, globular, or flattened at the poles, bright yellow, two 

 to four inches in diameter, composed of a juicy, edible pulp, divided into 10-13 

 cells, each cell with 1-3 seeds, the whole inclosed in a bright golden, tough rind. 

 In a state of cultivation the spines on the bi'anchlets are usually wanting. 



