566 CLXX. NAiADACBiE. (J. D. Hooker.) [Potamogeton. 



The Panjab, Thomson. Kashmie, alt. 5000 ft., Jacquemont, Ac— Distbib. 

 widely diffused especially in temp, climates. 



Stem terete. Leaves 2-6 in. ; submerged (if present) sessile, long, narrow, and 

 without a limb. Pedimcle stout. Drupelets ^ in. long. 



3. P. oblongrus, 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, drupelets 

 minute shortly beaked not keeled. Bngl. Bot. t. 2849. P. polygonifolius, 

 Fourr. in Mem. Acad. Toul. iii. (1788), 325 ; SooJc.f. Students' Brit. M. 

 Ed. 3, 431. P. digynus and P. elegans. Wall. Gat. 5177, 5178. 



Nepal, Wallich. Khasia Hills, alt. 4-5000 ft. J.D.ff. ^ T.T. Singapoee ? 

 Wallich. — DiSTBiB. Temp, and trop. regions of the old world. 



The more membranous leaves, shorter stipules, very slender peduncle and 

 spike, smaller flowers and minute drupelets not ^ in. long, distinguish this from P. 

 batons. 



4. P. javanicus, SassJc. in Verh. SatuwrTc. Ver. Ned. Ind. i. (1856), 

 26 ; floating leaves small ovate-oblong or elliptic acute at both ends 

 5-7-iierved longer than their petiole, submerged linear acuminate, stipules 

 ■j-l- in., peduncle slender, spike lax fld., drupelets i-orbicular beaked, ribs 

 often toothed or tubercled, beak hooked, Miq. Fl. Ind. Bat. iii. 750. P. 

 tenuicaulis, J^. Muell. Fragn. i. 90, 244 ; Bentk. Fl. Austral, vii. 171. P. 

 parvifolius, Buchen. in Brem. Ahhandl. vii. (1880), 32. P. heterophyllus, 

 Sam. in Wall. Gat. 5181. P. hybridus, Mich. ? Herb. Ind. Or. Hf. & 1. 



Plains of India j ascending the Himalaya to 7000 ft., in the N. West, and 

 9O0O ft. in Sikkim. Ehasia Hills, alt. 6000 ft.— Disibib. Trop. Asia, Africa and 

 Australia. 



Stem very slender, ieores \-\\ in. j blade twice as long as the petiole or longer 

 SpiTie -J— J in. ; flowers very small, in interrupted whorls ; peduncle as long or 

 longer. Sepals orbicular-obovate. Drupelets -^ in., turgid, beak stout. 



** Leaves all submerged, ovate oblong or broadly linear, translucent. 



5. P. perfoliatus, Zinn. 8p. PL 126 ; stem stout, leaves amplexioaul 

 ovate-cordate entire 5-9-nerved, peduncle short stout, drupelets hardly 

 keeled shortly beaked. Funth Enum. iii. 133; Beichb. Ic. Fl. Qerm. 

 vii. t. 29 ; Boiss. Fl. Orient, v. 17 ; Balz. & Gibs. Bomb. Fl. 248. 



Western Himalaya ; from Kashmir to Kumaou, alt. 4-8000 ft. Wbsteen 

 Tibet, alt. 8-14,000 ft. — Disteib. N. temp, regions, Australia. 



Stem terete, dichotomous. ieaiies 1-4 iu., margins scabernlous, upper opposite; 

 stipules small, caducous. Peduncle stout, not thickened upwards. Spi/fce dense-fld. 

 Sepals long-clawed. Drupelets i\ in., compressed, beak straight. 



6. P. crispus, Idnn. Sp. PI. 126; stem slender, leaves semiamplexi- 

 caul linear or linear-oblong crisped serrulate 3-nerved, peduncle curved 

 tapering upwards, spike few-fld., drupelets obliquely ovoid long-beaked. 

 Funtk Fnum. iii. 133 ; Beichb. Ic. Fl. Germ. vii. t. 29, 30 ; Boiss. Fl. Orient. 

 v. 17. P. tuberosus, Boxb. Fl. Ind. i. 472; Wall. Gat. 5174; Grah. Cat. 

 Bomb. Fl. 200; Balz 8f Gibs. Bomb. Fl. 248. P. crenulatus, J3on Prodr 

 22. 



Plains of India and Tempebate Himalaya ; from Kashmir to Bhotan alt 

 4-6000 ft. MuNUiPOEE, Watt—DisT-ElB. N. and S. temp, and subtrop. regions. 



Stem dichotomous, compressed. Leaves 1-3 it., alternate and narrowed at the 

 base, or opposite and amplexicaul, tip rounded ; stipules small, caducous. Peduncle 



