482 PHYTOGEOGRAPHICAL, REMARKS 



known part of Surinam agrees much more with that of French Guyana and 

 the lower course of the Amazon ; it is chiefly distinguished by the very 

 regular distribution of rainfall and temperature over the whole year. 



Plant formations and vegetation zones. 



The littoral part of Surinam is formed by an alluvial strip of land, 

 rising from the sea with a very ,gentle slope. In the eastern part of the 

 colony this strip is much narrower than in the western; on the Marowine 

 it reaches a breadth of 26 kilometres, on the Surinam river of 63, on the 

 Saramacca of 79, on the Coppenam of 70 and on the Nickerie of 85 kilo- 

 metres. This alluvium has been formed partly by the sea, partly by the 

 rivers, but the border between the two is not everywhere known and seems 

 to have a very irregular course. The nearly bare mud banks which extend 

 far into the sea, especially near the mouths of the rivers, pass on the side 

 of the land into a typical mangrove vegetation, chiefly consisting of Rhizo- 

 phora Mangle and Avicennia nitida, mixed with Conocarpus erectus, Bucida 

 Buceras, Laguncularia racemosa and Acrostichum aureum. As far as can be 

 judged from the little material collected of this part, it may be assumed 

 that this vegetation is practically equal to that of all low shores of northern 

 South America. 



The alluvial strip is broken by a number of shell banks, running parallel 

 to the shore and called „schelpritsen" in the colony. They rise for the most 

 part so far above their surroundings that they are not flooded by the tide 

 and as they form a more solid underground, they are overgrown with larger 

 trees which in some places rise above the low vegetation and make a quite 

 different impression from the mangrove. Marshes are found in various places 

 between these shell banks and where the shore is very flat, as is especially 

 the case in the western part of the colony, Coronie, but also more to the 

 east, on the Commewine, trees are altogether absent and are replaced by 

 plains overgrown chiefly with Cyperaceae. What circumstances give rise 

 to these formations is unknown still and can only be settled by an accurate 

 investigation in loco. 



In the east, on the mouth of the Marowine near Galibi, the mangrove 

 vegetation is lacking and a sandy beach is found. 



This region is followed by the greater part of the alluvial strip, namely 

 the part formed by the rivers and where the vegetation is no longer influ- 

 enced by the seawater. It was already remarked above that the borderline 

 between sea and river alluvium cannot be sharply drawn. This is particularly 

 noticed when going up a Surinamian river. Almost imperceptibly the true 

 mangrove vegetation passes into a freshwater vegetation, but along the 

 rivers the mangrove is found much farther inland than between the rivers. 

 Especially Avicennia is found at a great distance from the shore. The low 



