( 350 .) 
POTAMOGE'TON* *. 
Linnean Class and Order. Tetra'ndria f, Tetragy'nia. 
Natural Order. Fluvia'les, Vent. — Lindl. Syn. p. 248. ; Intr. 
to Nat. Syst. of Cot. p. 2S9. — Loud. Hort. Brit. p. 541. — Mack. FI. 
Hibern. p. 264. — Na.iades, Juss. Gen. PI. p. 18. — Sm. Gram, ot 
Bot. p. 66. — Rich, by Macgilliv. p.387. — Hook. Brit. FI. (4th ed.) 
p. 423. — InuxdatvE, Linn. — Alismace.e, De Cand. — Juncales; 
sect. Nayadin.e ; type, Nayadace^e ; Burn. Outl. of Bot. v. i. pp. 
403 & 413. 
Gen. Char. Cali/ x none. Corolla (fig. 1.) inferior, of 4 con- 
cave, equal, incurved, deciduous petals, with claws about as long as 
their limb. Filaments (see figs. 2 & 3.) 4, sometimes more, flat, 
very short. Anthers (see figs. 2 & 3,) nearly sessile, oblong, 
2-lobed. Germens (see fig. 4.) 4, alternate with the stamens. Styles 
generally none. Stigmas blunt, permanent. Seeds (see fig. 5.) 4, 
naked, roundish, tumid at the back ; compressed or angular at the 
inner margin. Embryo (fig. 6.) curved. Flowers sessile upon a 
spike or spadix, which issues from a sheathing braetca or spatha. 
Floating plants, with pellucid leaves. 
The single perianth ; and the 4 sessile, naked seeds ; will dis- 
tinguish this from other genera in the same class and order. 
O O 
Fourteen species British. 
POTAMOGE'TON NA'TANS. Floating Pond-weed. Broad- 
leaved Pond-weed. Sharp-fruited Pond-weed. 
Spec. Char. Lower leaves strap-shaped, membranous, or want- 
ing ; upper ones elliptical, roundish heart-shaped at the base, 
leathery, floating; all on long stalks, many-nerved, and distinctly 
cellular. Fruit keeled. 
Engl. Bot. t. 1822.— Ft. D.in. t. 1025.— Lint. Sp. PI. p. 182.— Huds. Ft. Angl. 
(2nd edit.) p. 74. — Willd. Sp. PI. v. i. pi. I. p. 712. — Sm. FI. B" ; t. v. i. p. 193. ; 
Engl. FI. v. i. p. 228. — With. (7th ed. ) v. ii. p. 255. — Lindl. Syn. p. 250. — Ilook. 
Brit. FI. p. 76. — Macr. Man. Br : t. Dot. pp. 223 & 224. — Lightf. FI. Scot. v. i. p. 
121. — Sibil). FI. Oxon. p. 61. — Abbot’s FI. Bedf. p. 37. — Bevies’ Welsh Bot. p. 
17. — Purt. Midi. FI. v. i. p. 104. — Belli. FI. Cant. (3rd edit.) p. 67. — Ilook. Fl. 
Scot. p. 57. — Grev. Fl. Edin. p. 40. — Fl. Devon, pp. 30 & 113. — Johnston’s Fl. of 
Berw. v. i. p. 41. — Winch’s Fl. of Northumb. and Durli. p. 10. — Walker’s 1’1. of 
Oxf. p. 43. — Bab. Fl. Bath. p. 47. — Murr. North. FI. p. 105. — Dick. Fl. Abred. 
p. 27. — Irv. Lond. Fl. p. 85. — Luxf. Reig. Fl. p. 15. — Mack. Catal. PI. Ircl. p. 19. ; 
Fl. Ilibern. p. 267. — PoLamog'.ton natans, Gvay’s Nat. Arr. v. ii. p. 33. — Pota- 
moyiton rotundifolium, Kay’s Syn. p. 148. — Potumogeito.i tatifolium, John- 
son’s Gcrarde, p. 821. 
Localities. — I n watery ditches, ponds, and slow rivers ; common. 
Perennial. — Flowers in July and August. 
Fig. 1. A single Flower. — Fig. 2. Slamens and Pistils. — Fig. 3. A separate Sta- 
men. — Fig. 4. Germens and Pistils. — Fig. 5. Fruit or Seed. — Fig. 6. Embryo. 
* From potamos, Gr. a river ; and geilon, Gr. a neighbour. All the species 
grow in water; and often present as beautiful an .appearance in clear streams and 
ponds, as the Fuel do in the ocean. They protect the spawn of fish, and harbour 
innumerable aquatic insects, their roots and seeds affording food to water birds. Sir 
W. J. Hooker. — Chamisso and Sciilechtendal have well illustrated this genus ; 
see Linnoca, v. ii. p, 159, t See folio 46, note t. 
