210 AMONG THE WILD FLOWEKS:. 
corolla—is in four small segments, sometimes 
absent. 
In the Linn: System they are in Cl TV,, 
Tetrandria ; the genus gives name to the Nat. 
Ord, POTAMOGETONACE&. 
The stamens of the Pondweed are 1, 2, or 
4. P. natans may be commonly seen with 
ovate or elliptic leaves floating on the water, 
and the green spikes rising among them; 
P. perfoliatus has the leaves, as the name 
implies, so clasping the stem that it appears 
to pass through them; the leaves of P. crisps 
are strongly waved, and crisped and serrate 
at the edges. 
The name Potamogeton is a Greek com- 
pound, meaning “inhabitant of the river.” 
On the surface of the same water with P. 
natans are sometimes seen the floating leaves 
and upright dense rose-coloured spikes of Poly- 
gonum amphibiun, one of the Persicaria family, 
more than half of whose 14 species are in- 
habitants of water or wet places. P. amphi- 
bium is a beautiful ornament, especially when 
it occupies the quiet pool of a slow river whose 
borders are well stocked with the taller aquatics. 
But, as the name implies, it is so far amphi- 
