ON SOME WATER PLANTS.
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distributed, being found throughout the north temperate
regions.
The Great Sedge or Bulrush, Scirpus lacustris, when growing
in little rivers like the Roding or in the still waters of the Nor-
folk Broads, sends up from thick creeping rhizomes clumps
of long stout cylindrical stems, some of which bear flowers at
FIG. 6.
their summits, while others are flowerless. The leaves form
short green or brown sheaths, with little or no development
of a free blade, folding round the stem bases; but when
growing in deep water in the Thames or Ouse, abundant float-
ing and submerged ribbon-leaves are produced, from two to
five feet long, which look like water forests as one passes over them
in a boat. They resemble the submerged leaves of Bur-reed,