FAMILIES OF FLOWERING PLANTS. 



30 



Cdladlum is a genus in which the leaves are highly ornamental, being 

 variegated in shades of pink, purple and green. Florists sell under 

 this name the common lawn plant called "Elephant's-ear," which 

 really belongs to the entirely different genus Colocasla^ and is highly 

 important in the tropics. It is there called f<(ro^ and is everywhere 

 cultivated for the arrowroot yielded by its enormous roots. Another 

 peculiar confusion of names is to be seen in the case of the calla of 

 cultivation, which belonos to the o-enus ArouJes. The genus Calhi, 

 containing a single species, €\ palirstr/.^, is a small bog herb of the 



Pig. 34.— The floating arum (Pislia spatlnilata), one-half natural 

 size. Original, 



northern United States, often called water arum, and bearing only a 

 superticial resemblance to the more pretentious plant of our window 

 gardens. Other ornamental genera of cultivation are Anthurium, 

 Pathos, and Jlonstera. Reference should be made to the peculiar 

 Pistia, a succulent free floating plant very different from an ordinary 

 arum, found in the streams of Florida and most tropical regions. 

 (See Fig. 84. ) 



Family Lemnaceae. Duckweed Family. This group is of un- 

 usual interest, as containing the smallest known flowering plants. 



