iv TROPICAL FLORAS 69 



the centre they descend into the earth and form a central 

 trunk. A French botanist, M. Emm. Liais, says of this 

 species : " If we dig we find how all these small shrubs, 

 apparently distinct, are joined together underground and 

 form the extremities of the branches of a large subterranean 

 tree which at length unite to form a single trunk. M. Renault 

 of Barbacena told me that he had dug about 20 feet deep to 

 obtain one of these trunks." The large subterranean trees 



FIG. 7. ANDIRA LAURIFOLIA (Papilionacese). 



with a trunk hidden in the soil form one of the most singular 

 features of the flora of these campos of Central Brazil. 



The above facts are from Mr. Warming's book, supple- 

 mented by some details in a letter. They are certainly very 

 remarkable ; and it is difficult to understand how this mode 

 of growth has been acquired, or how the seeds get so deep 

 into the ground as to form a subterranean trunk. But 

 perhaps the cracks in the dry season explain this. 



A large part of these campos is burnt every year at the 

 end of the dry season, but as the vegetation is scanty the 



