1 68 DICOTYLEDONS 



Cultivated plants — Uses, etc. — The root of the Chicory 

 (Cichoriuni) which has capitula of blue ligulate flowers, is the 

 source of the substance "chicory," which is used in the 

 adulteration of Coffee. The Lettuce {Lactucd) has yellow 

 ligulate flowers. The tubers of the Jerusalem Artichoke 

 (Helianthus tuberosus) are subterranean stems which are con- 

 sumed as vegetables. But the " tubers " of the Dahlia are very 

 thick adventitious roots. The Artichoke {Cynard) possesses 

 fleshy capitula which are edible. The Marigold {Calendula) 

 has carpellary disk-flowers, and staminate ray-flowers : it often 

 produces several kinds of fruits in the same inflorescence. 

 The so-called double varieties of Dahlia, and the cultivated 

 varieties of Chrysanthemum, are plants whose disk-flowers have 

 been artificially converted into false ligulate flowers. Other 

 familiar garden plants are Cineraria, Gaillardia, Calliopsis, 

 Pyrethrum, Everlasting Flowers {Helichrysum). 



