ZANNICHELLIACEAE 17 
turgid, 4—4.5 mm. long, S-kecled— (Heanmuar. -PONDWEED.)—Ponds, various 
provinces, Fla. to Ark., B. C., 
4. P. amplifolius Tuckerm. Leaves of 3 kinds, the lower submerged ones with 
WEAR ird acute at each end, the upper 'subm merged ones mostly smaller 
han the lower ones; 2 ll to oval, the floating unn with thiek ovate 
Es oval blades ide d at the base: drupe elet turgid, 4—5 mm. long, the middle 
keel prominent. Mire be Pon various provinces, Fla. to Ark., Calif., 
B. C., and N. S. 
. P. epihydrus Ra f. Leaves of 2 ki nds, the submerged m linear 5-nerved 
blades the up ae ir elliptie or obovate blades 3-8 em. long: drupelet 
ad -obovoid, long, the middle keel sharp. [P. pe nnsylvawicus 
Willd., = Nu a Ci & Schlecht.]|—Ponds and streams, various provinces, 
S. C. to . C. and Newf. 
6. P. heterophyllus Schreb. Leaves of 2 kinds, the submerged narrowed up- 
ward, inconspicuously reticulate, the floating ones with oval or elliptic blades 
15-4 em. long, abruptly pointed: drupelet 1.5-3 mm. long, i E 3- 
Pe — Stil or flowing water, throughout U. S. and S Can.—(W. I., Mex 
Eurasia.) 
P. fluitans Roth. Leaves of 2 kinds, the submerged long-petioled, with 
cds blades, the eae ones with ellipti ic, sometimes gene so, long- 
petioled blades 4—15 cm. long, bie acute: drupelet 3.5-4 mm. long, the 
Ru Er lx ent. "IP. americanus Cham. & Schlecht., P. nee Tuck- 
and ponds, various pre ee, Fla. to Calif., B. C., and N. B.— 
(W. I5 Mer., | » 
8. P. angustifolius Berch. & Presl. Leaves of 2 kinds, the submerged with 
ri 5—15 em. long, the on ones with elliptie, nearly sessile blades 3—10 
lon 
ng: drupelet 2.5-3.5 mm. long, 3-keeled, abru pri y pointed. [P. Zizii 
Roth. d and 3 m various provinces, Fla. to Tex., Calif., and Me. 
. P. lucens L. Leaves of 1 pc e. d Nc ud or mater 
or oval above, 5-20 em. lon ee and often rulate at the 
eke nearly sessile: dru pelet 3 mm. os tant. Pons wir Ce Bun» 
WEED.)—Ponds, various provinces, Fla. to Tex., Calif. and N. S.—(W. I. 
Mez., O. W.) 
10. P. d ded L. Leaves submerged; blades suborbieular to ovate or 
lanceolate, 2 long, usually obtuse and serrulate at the apex, cordate- 
perfoliate: a 2.5-3 mm. long, obscurely 3-keeled.—Slow rivers and 
ponds, various provinces, Fla. to Tex., Minn., HE Newf.—(Enu.) 
11. P. Curtissii Morong. Leaves submerged; blades linear-filiform, 1—4 
deris l-ribbed, hair-tipped: drupelet not seen.—Tidal creeks, Blackwater River 
region, W Fla. 
12. P. pis Raf. Leaves very many, dry aes eue 2 or filiform, 
1.5-5 . long, 3-ribbed, acute: drupelet mm. long, middle keel 
crest like. [ P. d iier Streams and EA x provinees, 
Fla. to Calif., B. C., and N. B.—(W. I., Mez.) 
13. P. pusi nee L. uds numerous, sia pid linear Ey linear- 
filiform, 2-8 em. long, 3-ribbed, aeute: oid t 1.5-2 mm. long, the middle 
keel not erest- ike, or cbsolete.—Slow ams and Ponts various ae 
Ala. to Calif., B. C., N. S., and N. C.— "Mem. Eurasia.) 
2 
