194 HISTOLOGY OF MEDICINAL PLANTS 



INULIN 



Inulin is the reserve carbohydrate material found in the 

 plants of the composite family. 



The medicinal plants containing inulin are dandelion, chicory, 

 elecampane, pyrethrum, and burdock. Plate 77, Figs, i and 2 

 show masses of inulin in dandelion and pyrethrum. 



In these plants the inulin occurs in the form of irregular, 

 structureless, grayish- white masses (Plate 77). In powdered 

 drugs inulin occurs either in the parenchyma cell or as irregular 

 isolated fragments of variable size and form. Inulin is structure- 

 less and the inulin from one plant cannot be distinguished 

 microscopically from the inulin of another plant. For this 

 reason inulin has little or no diagnostic value. The presence 

 or absence of inulin should always be noted, however, in examin- 

 ing powdered drugs, because only a few drugs contain inulin. 



When cold water is added to a powder containing inulin it 

 dissolves. Solution will take place more quickly, however, in 

 hot water. Inulin occurs in the living plant in the form of cell 

 sap. If fresh sections of the plant are placed in alcohol or 

 glycerine, the inulin precipitates in the form of crystals. 



MUCILAGE 



Mucilage is of common occurrence in medicinal plants. 

 Characteristic mucilage cavities filled with mucilage occur in 

 sassafras stem (Plate 66, Fig. 2), in elm bark (Plate 66, Fig. i), 

 in althea root, in the outer layer of mustard seed, and in the 

 stem of cactus grandiflorus. In addition, mucilage is found 

 associated with raphides in the crystal cells of sarsaparilla, 

 squill, false unicorn, and poly gona turn. 



When drugs containing mucilage are added to alcohol, 

 glycerine, and water mixture, the mucilage swells slightly and 

 becomes distinctly striated, but it will not dissolve for a long 

 tune. Refer to Plate 79, Fig. 6. 



Mucilage, when associated with raphides, swells and rapidly 

 dissolves when added to alcohol, glycerine, and water mixture. 

 The mucilage is, therefore, different from the mucilage found 

 in mucilage cavities, because it is more readily soluble. 



In coarse-powdered bark and other mucilage containing 



