MOOTS AND RHIZOMES. S03 



Tropics. It is a leafless tree, with smooth bark; the 

 branches are cord-like, pendulous, striate, and have sheath- 

 ing joints, much resembling the stems of the Scouring 

 Rush (^Eqwiseiurri). The flowers are inconspicuous, the 

 staminate in spikes or catkins, and the pistillate in heads, 

 eventually becoming a woody cone. The wood is brown in 

 color, and has many small ducts. The Medullary Eays are 

 not visible to the naked eye. The wood is difiieult to split 

 and cut. The bark furnishes a dye, and the ashes are used 

 in the manufacture of soap. It is a valuable timber for 

 ship-building. This tree and other species of the same 

 genus are cultivated as ornamental curiosities. 



ROOTS AND RHIZOMES. 



291. The dye Madder is furnished by a small plant of 

 the order Hubiacece, namely, Ruhia tinetoria. Its roots are 

 perennial; they send up annually slender-jointed, square 

 stems, a few feet high; the leaves are whorled, and the 

 plant resembles some species of Galium. The flowers are 

 in clusters, and have a rotate yellow corolla. Madder was 

 known to the ancient Greeks and Romans. It is now 

 cultivated in Europe, Asia, Australia, and America. It is 

 seldom raised from the seed, but usually from stolons ; 

 after two years the slender roots can be used. The outer 

 cortex of the root is reddish-brown. All the membranes or 

 cell-walls are yellow or red. The coloring matter exists 

 dissolved in the cell-sap ; and in drying, the walls become 

 tinged. Many chemical constituents are contained iu the 

 root, among which may be mentioned Rubian, a brown, 

 amorphous, gummy substance, soluble in water and alcohol, 

 but insoluble in ether. After the roots are dug, they are 

 dried, then flailed to remove the cuticle; they are then 

 crushed and ground. Madder is used for dyeing red. 



