He listh under the shady trees; or, under the lotus trees (Revised Version). The Lotus sylvestris, or Lotus Cyrenaiea, "grows abundantly an the hot banks of the Upper Nile" (Cook). and is thought to be the tree here intended (Schultens.
Cook, Houghton, and others). But the identification is very doubtful. The dense shade of trees is sought alike by the hippopotamus and the elephant. In the covert of the reed, and fens. This is exactly descriptive of the hippopotamus; far less so of the elephant.
Gordon Cumming says, "At every turn there occurred deep still pools, and occasional sandy islands, densely clad with lofty reeds Above and beyond these reeds stood trees of immense age. beneath which grew a rank kind of grass, on which the sea-cow (hippopotamus) delights to pasture".