V] 



EXTERNAL RESEMBLANCE. 



97 



serve to illustrate the possibility of confusion not merely between 

 different genera of the same family, but even between members 

 of different classes or groups. The long slender branches of the 

 Polygonum represented in (fig. 21) would naturally be referred 

 to Equisetum in the absence of the flowers (fig. 20 B), or without 

 a careful examination of the insignificant scaly leaves borne at 



Fig. 22. Kaulfussia asculifolia Blume. From a specimen from Java in the 

 British Museum herbarium. ^ nat. size. 



the nodes. The resemblance between Casuarina and Ephedra 

 and the British species of Equisetum, or such a tropical form as 

 E. debile, speaks for itself. 



7 



