137 
P. crtsptts. Curled Pond-weed. Fig. 1361. 
Leaves submersed, lanceolate, serrated, waved at the margins. P 00 I 3 
andditches. JuneandJuly. Greenish. (§) E.B. 1.1012. E.B.2. 
242. H. fy Am. 481. Bab. 352. Lind. 249. 
P. oblongus. Oblong-leaved Pond-weed. Fig. 1362. 
Leaves all stalked; upper ones floating, oblong-elliptical; lower 
linear-lanceolate. Spike cylindrical, on a cylindrical stalk. Ditches and 
pools. Perenn. July. Brown. (§) E. B. Supp. 2849. H.fy Am. 
484. Bab. 350. Lind. 250. 
P. praslongtjs. Long-stalked Pond-weed. Fig. 1363. 
Leaves narrow-oblong, stem-clasping, obtuse and hooded at the end. 
Peduncles very long, cylindrical. Pools. Perenn. July. Brown, 
(f) E.B. Supp. 2858. H. fy Am. 481. Bab. 352. Lind. 334. 
P. compressus. Flat-stalked Pond-weed. Fig. 1364. 
Leaves linear, obtuse, 5-ribbed. Stem compressed. Ditches. Perenn. 
June and July. Brown. (|^) E. B. 1. 418. E. B. 2. 243. II. fy Am. 
480. Bab. 352. Lind. 249. 
P. gramineus. Grassy Pond-weed. Fig. 1365. 
Leaves linear-lanceolate, obtuse, 3-ribbed. Stalk shorter than the 
stipules. Ditches. Perenn. July. Brownish, (f) E.B. 1.2253. 
E.B. 2. 244. H. Am. 480. Bab. 353. Lind. 249. 
P. ptjsilltjs. Small Pond-weed. Fig. 1366. 
Leaves linear, obtuse, 3-ribbed. Stalks much longer than the 
stipules. Ponds and ditches. Perenn. July. Brown, (f) E. B. 
1. 215. E. B. 2. 245. H. Am. 480. Bab. 353. Lind. 249. 
P. acutifolius. Sharp-leaved Pond-weed. Fig. 1367. 
Leaves linear, 3-ribbed, with many parallel veins. Stem flat. 
Ditches. Perenn. July. Brown. (§) E. B. Supp. 2609. E. B. 
2.245*. H. Am. 481. Bab. 353.' Lind. 333. 
P. zoster^efolius. Grass-wrack Pond-weed. Fig. 1368. 
Leaves broadly linear, 3-ribbed, with many parallel veins. Stalks 
swelling upward. Stem flat. Ponds and lakes. Perenn. July. Brown, 
(f) E. B. Supp. 2685. E. B. 2. 245**. H. Am. 481. Bab. 
352. Lind. 249. 
P. pectinatus. Fennel-leaved Pond-weed. Fig. 1369. 
Leaves bristle-shaped, sheathing. Stipules adnate. Spike inter¬ 
rupted. Green. (§) E.B. 1. 323. E.B. 2.246. H. Am. 479. 
Bab. 354. Lind. 248. 
P. densus. Close-leaved Pond-weed. Fig. 1370. 
Leaves ovate, opposite, crowded. Stipules wanting. Ditches and 
pools. June. Brown. (|) E. B. 1. 397. E.B. 2. 247. H.fy Am. 
479. Bab. 354. Lind, 248. 
T 
