VEGETATION AT SANTAREM 149 
there a taller, but never a lofty, tree inter- 
mixed — and most of them bearing showy blossoms, 
fringed the beach of the Tapajoz. Where the 
shore rose abruptly inland, the fringe of gapo was 
narrow ; but where it was nearly flat, as at the 
mouths of rivulets, there was a great breadth of 
that peculiar arborescent vegetation which flourishes 
only where the plants are wholly or in part sub- 
merged during some months in the year, being to 
them a sort of hibernation. The gapo vegetation 
of the Tapajoz has quite the same character as that 
of the Rio Negro, where I afterwards found several 
of the identical species of the Tapajoz, especially 
certain Leguminifers, such as Cmnpsiandra lauri- 
folia, Benth. ; Outea acacicefolia, Benth. ; Leptolobium 
nitens, Vog. ; and a Chrysobalan, Couepia rivalis, 
sp. n. The first of these is a low spreading tree 
or shrub, bearing a profusion of flowers, white 
within, rosy without, not unlike those of the peach 
or almond, but grouped in large corymbs. On the 
extreme edge of the gapo it sometimes forms a 
continuous fringe of miles in length, especially by 
the Rio Negro. The flowers are followed by pods 
containing large flat beans, which little Indian boys 
find suitable for making ducks and drakes with ; 
and their mothers grate down and (having got rid 
of the bitter narcotic principle by straining and 
baking) make passable farinha thereof ; but this is 
only when mandiocca runs very scarce. 
[The accompanying photographic print of the 
gapo vegetation of one of the tributaries of the Lower 
Amazon near Para shows conspicuously two species 
found here by Spruce. The small tree in the fore- 
ground with conspicuously mottled trunk is that 
