421 



FIG. 403. Protect cynaroides. (After BAILEY.) 



former belongs the Bastard Toad-flax (Comandra umbellata) ; to the latter the 

 American Mistletoe (Phoradendron, Fig. 404) and Arceuthobium. The great 

 majority of the Sautalales are tropical plants. 



Order XII. Aristolochiales 



The Aristolochiales comprise three fami- 

 lies, of mostly tropical plants, of which two, 

 the Rafflesiacese (Fig. 405) and Hydnoraceae, 

 are parasites of the most pronounced type. 

 These plants live within the bodies of other 

 plants, much as a Fungus does, and their 

 vegetative organs are reduced to an irregular 

 thallus, which may closely resemble the 

 mycelium of a Fungus. The flowers in 

 Rafflesia are of enormous size, sometimes 

 a metre in diameter. 



The Aristolochiacese, the third family, are 

 herbaceous or woody plants, with curious 

 flowers, often of large size. Asarum Cana- 

 dense (Fig. 406) is the common Wild-ginger, 

 and several species of Aristolochia also 

 occur wild. Of the latter, A. sipho is a 

 common ornamental climber. 



Order XIII. Polygonales 



FIG. 404. Phoradendron flaves- 

 cens. (After BAILEY.) 



The Polygonales include the single fam- 

 ily Polygonaceae, well represented within the United States by numerous species 



