342 



F I L I C E S. 



3. AZOLLA, Lam. 

 1. Azolla Magellanica, Willd. 



Azolla Magellanica, Willd. Spec. PL 5, p. 541 ; Kaulf. Enum. Fil. p. 273; Gaud. 



Bot. Freyc. Voy. p. 406. 

 Salvinia Azolla, Kaddi, Plant. Brazil. 1, p. 2, t. 1, f. 3. 



Hab. Vicinity of Rio Janeiro, Brazil. Shores of Rio Negro, Pata- 

 gonia. Chili. Callao, Peru. 



This elegant little plant is very plentiful on the muddy shores of 

 the Rio Negro, growing in patches 3 to 6 inches in diameter. In 

 Chili, we found it still more abundant, inhabiting creeks or pools of 

 still water by the margins of streams. The plants from these two 

 countries are identical, while the fronds of the Peruvian plant are 

 much larger and more lax in their growth; but this is to be attributed 

 rather to the warmer climate than to any specific distinction. 



2. Azolla microphylla, Kaulf. 



Azolla microphylla, Kaulf. Enum. Fil. p. 273; Hook. & Am. Bot. Beech. Voy. 

 p. 162. 



Hab. Vicinity of St. Clara, California : in pools of standing water. 



The only difference we can detect between this and the preceding 

 species consists in the much smaller size of the present plant ; and 

 perhaps the margins of the leaves are not quite so decidedly membra- 

 naceous. 



