Oe P, cramineus Le var. craninif 
olius Fries, 
otems simple or branching, 
very slender, the internodes abo 
floating leaves leathery, 3-7 om 
rounded et both cnds, on slender 
submerged leaves sessile 
or linear-lonceolate, 3-7-nerved 
thick et maturity, on ~eduncles 
$ U ‘ ne hee il r aan ae acl 
nuvlets °,5 ma. long, obscurcly kocled, 
ut _ccoualling the leaves; blades of the 
« long, 1.5-5 cm. wide, oval, obtuse, or 
pecioles usually 1-2 times as long «as the 
» Mostly 3-12 cm, long, 3-6 mm, wide, linesr 
3 spikes cylindrical, 2-4 om, long, 7-8 mm, 
o=8 om. long, twice es thick «as the STOMS 3 
(P. heterophyllus Schreb.) 
Freevent in shallow pools and slonr late margins on muddy bottoms; the 
mtingte Lake Pend Oreille, Leiberg 195 
e 
> 
3 Leke Vocur d'Alene, wDling & Houek 10051; 
7. P, -raelongus wulf, Stoms wh 
very leafy; leaves all submerged 
lo-50 mn. wide, more or icss cla 
ive, much-branched, or zigezeg, 1-2 m, long, 
» mostly oblong-lanceolate, 10-20 em, long, 
——s ee 
Sping «at the base, somewhat crispeds; stivules 
sistent; peduncles stout, about ecual to the 
nearly 1 cm, thick in fruit; nut 
reel 
be 4 & 
S. P. Rithardsonii (A. Benn.) Ry 
rr?) = rz r == 
on out avuneles uegcO cm, lon 
- }- a oO 
si -* 
&&» the spikes cylindrical, 2-5 cm, longs, 
lots smooth, mostly with o single sharp 
db. Stems branching, all leaves submer red 
» <-10 om. long or more, acuminate, claspins 
26 the bese, stron:ly wavy; ewe stipules 1-2 em, long, soon breaking into 
ws 
ee eee ee 
5} 5 a4 = * 2 a «a es, ety Ps fae i i 
hreass; spilces sev real, evlindy deal, 2-5 em. lon:, 8+9 mm, thick in “x ng 
