66 BOTANY OF THE VOYAGE OE H.M.S. HERALD. 
the heavy surf washing theu' tops, apparently without injuring or checking their growth ; 
indeed, so -well has nature pro^dded for them, that the seed of the Rhizophoras begins to 
germinate while the fruit is yet attached to the tree, and it is not until it has sprouted out 
to the length of some inches that it drops, as a young plant, into the mud below. Rivers, 
as far as they are subjected to the influence of the ebb and flow, are full of Mangroves, and 
the highest Rhizophoras, which, growing always on that side where there is the deepest water, 
assist the natives in conducting their canoes through the mud-banks. On the sand of the 
sea-beach the Ipoinoea pescapra grows in wild luxuriance, prodiTcing runners often more 
than two hundred feet long. Higher up, where the ground is firmer, are groves of Cocoa- 
w 
nut Pahns, poisonous Manzanillo- trees, and spiny Prosopises and Pitajayas, or thickets of 
Crescentia cucurbitina and Paritium iiliaceum. 
Par different is the vegetation of the savanas. The ground, being level or slightly 
midulatcd, is clothed diu-ing the greater part of the year with a turf of brilliant green. 
Groups of trees and bushes rise here and there ; silvery streams, herds of cattle and deer, 
and the isolated huts of the natives, tend to give variety to the scene, while the absence of 
Palms and Tree-ferns imparts to the whole more the appearance of a Eiu-opean pai'k than a 
tract of land in tropical America. The tiu-f is almost as dense as in an English garden, and 
contains, besides numerous kinds of grasses, many elegant Papilionacece, Polygalem, Gen- 
tiatiea, and Violacem ; the sensitive plant {Mimosa pudica^ Linn.) prevails in many localities, 
shutting up its tender leaves even upon the approach of a heavy footstep. The clumps of 
trees and shrubs, over which the Garumos and Pavas are waving their large foliage, are 
composed of Myrtacem, Melastomea, ChrysohalanecBj Papilionacece, Verhenacem, CompositcSy 
Billeniacem J Anonacea, Malpigldacem^ and Acantliacece^ and overspread by ConvoIcidacecB, 
Aristolochice, Apocynem, and other climbing or twining plants. OrcMdece are plentiful in 
the vicinity of the rivers, where the trees are literally loaded with them. The Vainilla 
{Vanilla sp.) climbs in abundance up the stems of young trees, and often increases so much 
in weight' as to cause the downfall of its supporters. The Chumicalcs, or groves of Sand- 
paper-trees {Curatella Americana^ Linn.), form curious features in the landscape. They 
extend over whole districts, and their presence indicates a soil impregnated with iron. The 
trees are about forty feet high, have crooked branches — an approximation to the twining 
habit of the tribe, and their paper-like leaves, if stirred by the wind, occasion a rattling 
noise, which strongly reminds one of the European autumn, when northerly breezes strip 
the trees of their foliage. 
Eorests cover at least two-thirds of the whole territory. The high trees, the dense foliage, 
and the numerous climbing and twining plants, almost shut out the rays of the sun, causing 
a gloom, which is the more insupportable as all other objects are hidden from view. Rain is 
so frequent, and the moisture so great, that the burning of these forests is impossible ; a 
striking difference to those of the temperate regions, where a fire often consumes extensive 
woods in a very short space of time. Plowers are scarce in proportion to the mass of leaves 
