170 CXXXVIII. NAIADER. [ Potamogeton. 
The genus is dispersed in the ws or subs d — Se ies ers part of the 
globe. Of the nine Aus pecies seven are c rate regions 
especially in lie: Old World, uM extends Nou Bae End dis 9m i the a 
i and one only is endemic but more nearly allied to American than to 
cies 
— deyv the flowers as unisexual, describing the stamens as distinct ke 
flow the carpels of the Rand as separate female flowers, a view in whi 
vani a difficult to concur 
SEC I.— Leaves all ana and petiolate with floating lamine, or the lower ones 
AN. Stipules connate within the petiole. 
Fruit-spikes csi: p not ning a complete coil. 
Fl 
s usually 2 to 4 in. orlonger. Nutlets 
oi e Miley beaked 
Floating leaves H to à in. long. Nutlets distinctly 
beaked . 
. 2. P. tenuicaulis 
Nisikchose globular. "Nutlets LI not. beaked. Seed z 
forming a complete coil . . 8. P. Drummonda. 
l. P. natans. 
EOTION IL.— Leaves all s sei sessile or nearly so, those under cha pahi a 
cone Jes opposita, the ccs alternate. Stipules connate within the petiole, often very 
zem nón SCA dt ovate or finie DES e 
£p. E 
Paves oblong-lanceolate, many-ne . 6. P. pralongus * 
ves w-oblong or rarel Mad ar, "usually 3-nerved, : 
. very obtuse, the margins often undulate-cri 6. P. crispus. 
Leaves narrow-linear. 
ear, obtuso or Parenti acute, 1-nerved. Pr. 
Spikes 4 i = peng or 7. P. obtusifolius. 
ves narrow-linear, EY Mis i- or or S-nerved. Spikes 
short n RUM Toydioser Seod fo Loy 
plete coil . 8. P. acutifolius. 
Secrion III 
TON all RES sessile or near ES so with sheathing margins i 
no distinct stipules. 
Leaves narrow-linear, l-nerved. Stems repeatedly dicho- $ 
E gg NP TS SE a kl... 9. P. pectinatus. 
l. P.natans, Linn.; Kunth, Enum. iii. 127.—U pper leaves or often 
the "wholé of them on long petioles, 
of a thick opaque texture, ova ate or 
broad, or rarely in smali 
ew eins 0 
; lower submerged leaves wie ly few a 
often xe 2d all submerged thin and narrow but xdg bo 
a 
and several-nerved. Stipules ike 
nnate, free from the petiole mem at the very beny Sp 
