ANACHARIS ALSINASTRUM, 
A NEW WATER WEED. 
(2EPRINTED FROM THE CAMBRIDGE INDEPENDENT PRESS.) 
REVISED BY THE AUTHOR. 
LETTER.—No. L 
Sir, 
A remarkable plant has recently made its appearance in 
the rivers Ouse and Cam, and already abounds to such a 
degree, as not only to impede navigation, but what is of far 
more importance in this fen country, threatens to injure our 
drainage. : 
It occurs in dense tangled submerged masses of consider- 
able extent, and is so heavy, that when cut, (instead of rising 
to the surface and floating down to sea, like other weeds) 
_ it sinks to the bottom. It is this property which is likely 
to make it injurious to drainage. The intruder is so unlike 
any other water plant, that it may be at once recognized by 
its leaves growing in threes, round a slender stringy stem. 
The watermen on the river have already named it “ Water 
Thyme,” from a faint general resemblance which it bears to 
that plant. 
That it is new to our rivers here, is certain; watermen and 
fishermen pronounce it to be, (as I heard one of them call it 
the other day), “ a furreigner.” ; 
A 
