TYPICAL SWAMP AREAS. 63 
several acres are crowded with a dense growth of man- 
groves fifteen or twenty feet in height. 
The general characteristics of the mangrove, Rhizophora 
Mangle, may be briefly stated. 
From the main axis, numerous curving prop-roots are sent 
down into the mud, giving the tree the appearance of an 
inverted candelabrum. (Plate 22.) 
As these prop-roots branch repeatedly, they soon make 
an impenetrable tangle of the mangrove swamp. In addi- 
tion to this, the horizontal limbs send down perpendicular 
aerial roots which usually branch before entering the water 
or mud. 
The diameter of these roots is approximately the same 
near the tip as at the point of insertion. The seeds send 
out pointed radicles while on the tree. When mature they 
drop to the ground and the pointed end sticks into the soft 
mud, holding the body erect. It continues growing, the 
lower end soon becomes rooted in the earth, while the 
upper end develops a pair of leaves. The mud under the 
trees is usually covered with these vigorously growing 
seedlings. 
Associated with the true mangrove, there is usually 
found the false mangrove, Avicennia nitida, which affects 
a similar habitat. So far as the writer has observed, the 
latter never sends out aerial roots, though an interesting 
phenomenon was noticed upon a group of old trees growing 
in the edge of Walsingham Bay. From the main axis and 
large branches near the first fork, there were developed 
numerous short processes, similar to aerial roots except 
that they were only a few inches long and in clusters. 
(Plate 24.) 
Avicennia nitida possesses one characteristic not shared 
with Rhizophora so far as observed, viz., it sends up from 
the roots perpendicular processes to the hight of several 
inches. These are crowded about the area subtended by 
