AMERICAN MEDICINAL PLANTS 



61 



Description.— The white mustard grows from 1 to 2 feet in height. It is more 

 or less hairy, with stiff, spreading hairs. The lower leaves, which are 6 to 8 

 inches in length, are deeply lobed, but the upper ones are lance shaped. The 

 surface of the leaves is rough hairy. The light yellow flowers are borne in clusters 

 at the ends of the stems from about June to September. The narrow, spreading 

 seed pods which follow are rough hairy, contracted between seeds, and are about 

 an inch in length, containing numerous roundish, pale-yellow seeds. 



Part used. — The seed, the pods being collected when they are nearly ripe 

 but not ready to burst open. After drying, the seed may be readily threshed 

 or shaken out. In limited demand only. 



Figure 115.— White mustard (Brassica alba) 



Figure 116.— White oak (Quercus alba) 



WHITE OAK 



Querctis alba L. (Fig. 116.) 



Other common names. — Stone oak, stave-oak. 



Habitat and range. — The white oak is found in woods from Maine to Minnesota 

 and south to Florida and Texas but is most abundant in the North Central and 

 Middle Atlantic States. 



Description. — This tree is usually from 60 to 80 feet high, but in dense woods 

 it sometimes reaches a height of 150 feet. The trunk attains a diameter of 3 to 

 4 feet with many wide-spreading branches. The leaves are red and hairy when 

 young, becoming smooth and thin when older. In autumn they turn a beauti- 

 ful red. The leaves are 4 to 7 inches long, borne on short stems, and are usually 

 divided into five to nine lobes. When the leaves appear the very small greenish 

 or yellowish flowers are produced. The male flowers are borne in slender, usually 

 drooping spikelike clusters and the female flowers singly. The acorns mature 

 in the autumn. 



Part used. — The bark, preferably that from trunks or branches 10 to 25 years 

 old, which should be collected in the spring. The outer layer is first scraped off. 

 In limited demand only. 



WHITE PINE 



Pinus strobus L. (Fig. 117.) 



Other common names. — Northern pine, Wejonouth pine, American white 

 pine, American deal pine, soft deal pine, spruce pine. 



Habitat and range. — The white pine native in this country occurs in woods 

 from Canada south to Georgia and Iowa. 



