442 
VEGETATION OE 
white flowers ; and with regard to the frequency of their 
occurrence, it was not an uncommon thing for me to 
pass days travelling up the rivers, without seeing any 
striking flowering tree or shrub. This is partly owing 
to the flowers of most tropical trees being so deciduous : 
they no sooner open, than they begin to fall ; the Me- 
lastomas in particular, generally burst into flower in the 
morning, and the next day are withered, and for twelve 
months that tree bears no more flowers. This will serve 
to explain why the tropical flowering trees and shrubs 
do not make so much show as might be expected. 
From the accounts of eye-witnesses, I believe that the 
forests of the southern United States present a more gay 
and brilliant appearance than those of tropical America. 
Humboldt, in his ‘ Aspects of Nature,’ repeatedly re- 
marks on the contrast between the steppes of Tartary 
and the llanos of the Orinooko. The former, in the 
temperate zone, are gay with the most brilliant flowers ; 
while the latter, in the tropics, produce little but grasses 
and sedges, and but few and inconspicuous flowering 
plants. Mr. Darwin mentions the brilliancy of the 
flowers adorning the plains of Monte Video, which, with 
the luxuriant thistles of the Pampas, seems hardly 
equalled in the campos of tropical Brazil, where, with 
some exceptions, the earth is brown and sterile. The 
countless beautiful geraniums and heaths of the Cape 
cease on entering the tropics, and we have no account of 
any plants equally striking and brilliant supplying their 
place. 
What we may fairly allow of tropical vegetation is, 
that there is a much greater number of species, and a 
