I'OrAMOUKTON. 
437 
L. subcordate below, when pressed flat a ridge is formed on 
each side of the ha,se, joi7ited to their stalks a little helow the 
limb. Sep. stalked, roundly rhomboidal. Anth.-cells not 
parallel. Fr. greenish, slightly compressed, li- — 2 lin. long. — 
[Var. pj-olixus (Koch) is an early state having longer anfl narrower thin and semi- 
pellucid l.—P. fluitaris (Both), /. of £. xxvi. (1888) p. 273, is probably f. natans 
Iwxns, and P. crassiJoUus (Fryer), J. of B. xxviii. (1890) p. 3-21, t. 299, is P. 
nat<m$Y,angii,Hifoiius.'\ — Poiids, ditches, and slow Streams. P. VI. 
VII. E. S. I. 
2. p. poli/gonifo/ius (Pourr.) ; 1. all stalked, upper subcori- 
aceous floating oblong-elliptic or lanceolate subcuspidate, no 
leafless petioles, lower 1. linear-lanceolate, /r. minute blunt and 
rounded on the back, peduncle equal.— /". oblongusYiv., E. B. S. 
2849. — St. creeping below. Petioles longer than leaves, 
convex on both sides, not jointed below the limb. Lower 1. often 
very narrow. Spikes rather short and irregular. Sep. trans- 
versely elliptic, stalked. Fr. reddish, scarcely compressed, 1. lin. 
long ; a faint keel and lateral ridges when dry. f^. pseudo- 
fluitans (Syme) ; submerged 1. membranous linear-lanceolate 
narrowed at both ends. [7. conceJiata (Fryer); floating 1. few thinner, 
submersed 1. strongly net-veined.] — Ditches, Small Streams, and ponds. 
jS. Buttermere. Gap of Duuloe, Kerry. P. VII. E. S. I. 
3. p. Grifflth'ii (Ar. Benn.); .subDQerseii I. strap-shaped usually sessile or half, 
clasping wavy somewhat hooded pellucid 9 — Iti-veined, tioating 1. obovate- 
lanceolate blunt long-stalked more opaque, slip, long usually exceeding the inter- 
nodes, ped. slender nearly eciual.— of B. xxi. (1883) t. 235.— St. branched. 
Floating 1. green, submersed 1. slightly brownish. Sep. "roundish-oval broader 
than long." Spikes short. Mr Fryer considers this a hybrid, i'. poZj/gow'i/oJiusx 
?— Llyn-an-afou, Cam. Mr -I. E. Griffith. P. VI.— VIII. E. 
4. P. Drwcei (Fryer) ; submersed 1. elliptic-lanceolate pellucid strongly retiiiulat-f- 
veined throughout very long stalked, floating 1. obovate elliptic or oval narrovred 
at both ends, stip. very long, fr. broadly obovoid amtelii keeleil, heel tuhercled with 
conspicuous angles at the base, ped. thicker than the st. narrowed at both ends. 
A very distinct plant, producing but little fruit and possibly a hybrid.— R. 
Loddon, Berks. Mr G. C. Drace. P. Vll. VUl. E. 
■■' 5. J', colurdtus (Hornem.) : /. all shortly stalked membranous 
andpellticid bluntnot cuspidate nor plicate, upper elliptic, lower 
1. oblong,/r. minute rounded on the back when fresh keeled when 
dry, peduncle equal. — E. B. >S. 2848. P. vii. 45. P. planta- 
gineus (Ducroz ex K. & S.). — St. creeping below, branched, some- 
times throwing out long runners from its upper axils. L. all 
beautifully transparent and netted with veins, the upper often 
almost sessile and nearly orbicular, sometimes slightly cuspidate . 
