566 CLXX. NAIADACEZ. (J. D. Hooker.) [ Potamogeton. 
The PANJAB, Thomson. KASHMIR, alt. 5000 ft., Jacquemont, &c.—DISTRIB. 
widely diffused especially in temp. climates. 
Stem terete. Leaves 2-6 in. ; submerged (if present) sessile, long, narrow, and 
without a limb. Peduncle stout. Drupelets 1 in. long. 
3. P, oblongus, Viv. Fl. Ital. 2, t. 13; floating leaves long-petioled 
elliptic or lanceolate thinly coriaceous, submerged narrowly lanceolate, 
stipules 14 in. peduncle and dense-fld. spike very slender, dru elets 
minute shortly beaked not keeled. Engl. Bot. t. 2849. P. polygonitolius, 
Pourr. in Mem. Acad. Toul. iii. (1788), 325; Hook. f. Students Brit. Fl. 
Ed, 3, 431. P. digynus and P. elegans, Wall. Cat. 5177, 5178. 
Nepat, Wallich. KmasrA HiLLs, alt. 4-5000 ft. J.D.H.4 T.T. SINGAPORE? 
Wallich.—Distriz. Temp. and trop. regions of the old world. a 
The more membranous leaves, shorter stipules, very slender peduncle "e 
spike, smaller flowers and minute drupelets not A in. long, distinguish this from £- 
natans. 
4. P. javanicus, Hassk. in Verh. Natuurk. Ver. Ned. Ind. 1. (1850), 
26; floating leaves small ovate-oblong or elliptic acute at both, n 5 
5-7-nerved longer than their petiole, submerged linear acuminate, stipul " 
3-1 in., peduncle slender, spike lax fld., drupelets 4-orbicular beaked, Be 
often toothed or tubercled, beak hooked, Mig. Fl. Ind. Bat. iii, 750. 
tenuicaulis, F. Muell. Fragn. i. 90, 944; Benth. Fl. Austral. vu. 171 
parvifolius, Buchen. in Brem. Abhandl. vii. (1880), 32. P. heterophyllus, 
Ham. in Wall. Cat. 5181. P. hybridus, Mich.? Herb. Ind. Or. Hf. & T. 
Plains of INDIA; ascending the Himalaya to 7000 ft., in the N. West, ert 
Feed lc in Sikkim. Kmasra HILLs, alt. 6000 ft.— D1sTRIB. Trop. Asia, Africa an 
ustralia. 
Stem very slender. Leaves 4-1} in. ; blade twice as long as the petiole or longe" 
Spike 4-3 in.; flowers very Man in interrupted whorls peduncle as 1008 T 
longer. Sepals orbicular-obovate. Drupelets Ae in., turgid, beak stout. 
** Leaves all submerged, ovate oblong or broadly linear, translucent. 
5. P. perfoliatus, Linn. Sp. Pl. 126; stem stout, leaves amplexi 
ovate-cordate entire 5-9-nerved, peduncle short stout, drupelets hardly 
keeled shortly beaked. Kunth Enum. iii. 133; Reichb. Ic. Fl. Germ. 
vii. t. 29; Boiss. Fl. Orient. v. 17 ; Dalz. & Gibs. Bomb. Fl. 248. 
WESTERN HiMALAYA; from Kashmir to Kumaon, alt. 4-8000 ft. Wer? 
TIBET, alt. 8-14,000 ft.—DrsrRIB. N. temp. regions, Australia. site; 
. Stem terete, dichotomous. Leaves 1-4 in., margins scaberulous, upper opp 
stipules small, caducous. Peduncle stout, not thickened upwards. Spike dense 
Sepals long-clawed. Drupelets à in., compressed, beak straight. 
6. P. crispus, Linn. Sp. Pl. 126; stem slender, leaves semiampl 
caul linear or linear-oblong crisped serrulate 3-nerved, peduncle M 
tapering upwards, spike few-fld., drupelets obliquely ovoid long moat 
Kunth Enum. iii.133; Reichb. Ic. Fl. Germ. vii. t. 29,90; Boiss. Pr h. Cat. 
v. 17. P. tuberosus, Roch, Fl. Ind. i. 472; Wall. Cat. 5174; Gram 
Sr Fl. 200; Dalz & Gibs. Bomb. Fl. 948. P. crenulatus, Do" Prot. 
PLAINS of INDIA and TEMPERATE HIMALAYA; from Kashmir to Bhotan, - 
ft. MuxsNIPORE, Watt.—DisrRIB. N. and S. temp. and subtrop- reg + the 
Stem dichotomous, compressed. Leaves 1-3 in., alternate and narrowed 
base, or opposite and amplexicaul, tip rounded ; stipules small, caducous. 
