452 TETRANDRIA TETRAGYNIA. Potamogeton. © 
1. P. indicum. R. 
Creeping. Legves alternate, from narrow-lanceolate to 
elliptically oval, opaque, glossy, many-nerved, Anthers 
four pair, attached to the claws of the round concave petals. 
A native of the borders of fresh water lakes and ditches 
in the vicinity of Calcutta. Flowers in February and March. . 
Stems creeping. ‘The small simple roots which issue from 
the joints are all I can discover, for while the-plant‘advances 
_ from the apex, it decays at the opposite end, so that I do not 
think any~part of them exists for one year. Branches few, 
_ and like what I call the stems; they are all round, smooth, 
> 
oa shestiaods Shaitulled with. one. 0 
and jointed at various distances. Leaves alternate, except 
next to the flowers, and there often opposite, petioled, from 
narrow-lanceolate to elliptically oval, opaque, even, and very 
smooth, or rather glossy, entire, obtuse, obscurely many-. 
nerved ; size very various. Those that remain immersed are 
narrower, longer, more strongly marked with nerves, and 
sub-transparent. Petioles simple, not sheathing, length vari- 
ous, in plants left by the water much shorter than the leaves. 
Stipules solitary, axillary, sheathing, length of the petioles, 
slit halfway or more on the inside, Peduncles solitary, axill- 
ary, or opposite to a leaf, round, rather thicker, smooth, and’ 
nearly as long as the cylindric spike, which each supports. 
Flowers small, numerous, green. Calyx none. Petals long-' 
clawed, nearly round, incurved, fleshy ; concave within, con- 
vex on the back, penelennii ilemarniote Anithere; ne: 
Styles short, and thick. Stigmas a dark speck on the apex 
of the styles. Drupes obovate, smooth. Nut conform to the 
drupe, one-celled, Embryo curved, as represented) by Gert- 
ner in P. alten, vol, ii, t, 84, 
* 
2. P. tuberosum. R. 
ss oie Hike she roa ik 
