704 A TEXT-BOOK OF BOTANY. 



red color of the dried root is due. At present alizarin is made 

 artificially from anthracene, a coal-tar derivative. 



Morinda citrifolia, a shrub widely distributed in tropical coun- 

 tries, contains a red coloring principle in the flowers and a yellow 

 coloring principle in the roots, the latter being known as morindin 

 and resembling the color principle in madder. 



The pulp of the fruit of Cape jasmine (Gardenia jasminoides) 

 contains a yellow coloring principle resembling crocin, found in 

 Crocus. 



The stem and root barks of Button-bush (Cephalanthus occi- 

 dentalis), common in swampy regions in the United States, are 

 used in medicine (Fig. 391 ) . The barks contain a bitter glucoside, 

 cephalanthin, and a tasteless glucoside which is fluorescent in solu- 

 tion. Mitchella re pens contains a saponin-like body in the fruit 

 and a tannin and bitter principle in the leaves. Quite a number of 

 species of Galium (bedstraw) are used in medicine and for other 

 purposes. A principle resembling glycyrrhizin is found in wild 

 licorice (Galium circazans) , a perennial herb growing in dry 

 woods in the United States, and also in Galium lanceolatum, which 

 is found from Virginia northward to Ontario. The yellow bed- 

 straw (Galium veruni), naturalized from Europe, contains a milk- 

 curdling ferment. 



b. CAPRIFOLIACE^: OR HONEYSUCKLE FAMILY. 

 The plants are perennial herbs, shrubs, trees, or woody climbers 

 with opposite, simple or pinnately compound leaves. The flowers 

 are perfect, epigynous, regular, or bilabiate, and arranged in 

 corymbs. The fruit is a berry, drupe, or capsule. They are mostly 

 indigenous to the northern hemisphere. 



Viburnum prunifolium (Black haw) is a shrub or small tree 

 25 cm. in diameter. The winter buds are acute and reddish- 

 pubescent ; the leaves are ovate, elliptical, obtuse or acute at the 

 apex, somewhat rounded at the base, finely serrulate, glabrous, 

 and short-petiolate (Fig. 392) ; the flowers are white and in 

 nearly sessile cymes ; the fruit is a small, oval, bluish-black, 

 glaucous, inferior drupe. The root-bark is official. 



Viburnum Opulus (Wild guelder-rose or cranberry-tree) is 

 a shrub about half the height of V. prunifolium, with broadly 

 ovate, deeply 3-lobed and coarsely dentate pubescent leaves. The 



