TREES AND SHRUBS FURNISHING MEDICINAL BARKS. 13 



The long, loose, green, cylindrical aments, or catkins, are staminate and 



pistillate and are borne on different trees, appearing with the leaves in spring. 



A variety of this species, with yellowish green twigs and with loaves smooth 

 on the upper surface, is known as golden osier {S. alba var. vitelline (L.) 

 Koch), and is the most common form found in North America. 



Description of hark. — The white willow bark of commerce is generally in 

 tough, flexible strips, the outer surface smooth or slightly wrinkled, and of a 

 yellowish brown or grayish brown color. The inner surface varies from a light 

 brown to darker brown, and is marked with 1< mir. tine lines. White willow 

 bark has a bitter, astringent taste, but practically no odor. 



Collection, prices, and uses. — The best time to collect white willow bark is 

 in the spring when the sap begins to flow, at which time it is easy to remove. 



White willow bark should not be kept very long, ;is the salicin content 

 diminishes with age This bark itself is not official in the United States Phar- 

 macopoeia, but the glucoside salicin obtained from it is so recognized. The 

 medicinal properties of willow bark depend upon its two most important con- 

 stituents, salicin and tannin. 



Salicin has tonic, antiperiodic, and febrifuge properties, and is occasionally 

 employed in rheumatic affections. 



The wood of white willow furnishes a very pure charcoal which is used in 

 the manufacture of gunpowder. The young branches, known as osiers, are 

 much nsed in the manufacture of baskets, etc. 



The prices paid to collectors range from 2 to ."> cents a pound. 



Oth< r species. — Roughly speaking, the willows, or Salix species, may be said 

 to be divided into two classes, those with yellowish twigs and those with 

 reddish or purplish twigs. Most of the yellow-barked species belong to the 

 " crack willows."' which have their twigs attached in such a manner that they 

 break off very easily. It is claimed that the red or purple barked twigs con- 

 tain the most salicin. while those with yellow twigs are richest in tannin. 



Of those containing the most salicin may be mentioned the crack willow, 

 or brittle willow {Salix fragilis L. t. This, a native of Europe, has escaped 

 from cultivation in this country, and occurs from Massachusetts to New Jersey 

 and Pennsylvania. It is a tall and slender tree, the trunk covered with a 

 rough gray bark, and the twigs with reddish green bark. At the point of 

 attachment the twigs are very fragile and break off readily. The twigs when 

 planted grow very rapidly. The leaves are 3 to 6 inches in length, long pointed 

 and narrowing toward the base, smooth, dark green on the upper surface, and 

 of a lighter color underneath, and with margins slightly toothed. The flowers 

 appear in April or May; the fruiting catkin is rather loose and about 3 to 5 

 inches in length, while the staminate or male catkin is only about 1 or 2 inches 

 long. 



Another species employed in medicine is the black willow, pussy-willow, or 

 swamp-willow {Salix nigra Marsh). This is a native willow and occurs along 

 the banks of rivers from Canada to Florida : it is not found west of the Great 

 Plains, except in southern New Mexico and Arizona and isolated in California. 

 It is tall and has a rough dark brown or black bark, and brittle yellowish 

 branches. The leaves are narrowly lance shaped, and the catkins (pussy- 

 willows) appear about the same time as the leaves, the male catkins about 1 

 to 2 inches long, and the female catkins as long as .'5 inches, spreading apart 

 in fruit. The bark of this species is used in medicine and the fresh aments. or 

 catkins, are also employed. 



"The National Standard Dispensatory, 1905 

 139 



