I'OTAMO&ETON. 363 



1985 (not R.). — St. very slender, sliglitlY branched. Floating 

 1. not always piesent with, the flowers. Uppermost stip. appa- 

 rently with '2 stronger dorsal ribs. — Streams, rare. Between 

 Bodafon and Lligwy, Angleaea. Buttermere. P. VII. VIII. 



B. S. ? 



6. P. spargaimf6lvm (Laest. !) ; submersed I. linear narrowed 

 at both ends very long sessile entire not apicnlate with many 

 parallel vei7is next the midrib, floating 1. subcoriaceous lanceolate 

 long-stalked, stip. very long not winged, fr. " acutely keeled " 

 (Fr.). — St. very slender, slightly branched. Floating 1. often 

 wanting. Submersed 1. sometimes 2 ft. long, very narrow, few- 

 veined with additional parallel veins closely placed next the 

 midrib. L. very much longer than those of P. lanceolatus and 

 withput the chainlike network Ped. very long, thick, equal. — 

 Fries's plant from Lapland is certainly the same. — In the river 

 at Ma'am, Galway. Mr. T. Kirk. Iliv«r Boyne near Navaa. 

 I>r. J). Moore. I. 



7. P. lieterpphyVlus (Schreb.) ; subjnersed I. lanceolate narrowed 

 at both ends sessile mimitely deniicidate and apiculate, floating 1., 

 subcoriaceous elliptic stalked; stip. broadly lanceolate blunt aa'if A 

 2 stout prominent ribs, lower ones linear-lanceolate, /r. blunt on 

 the back, peduncle thicker titan the stem swelling vpwards. — JE. £. 

 1280. JR. vii. 41 — 43. P. gramineus Fries, not Xinn. — St. much 

 branched below. Submersed 1. wavy. Lower stip. without the 

 two strong ribs and equally veined, upper ones widely spreading. 

 Di'v fc.. sightly marked with 3 ridges on the back. — Ponds and 

 ditches. P. VI. Vn. ' E. S. 1. 



8. P. iiitens (Web.) ; svbtnersed I. lanceolate rounded bekno and 

 half cUi^ng wavy at the edge, floa/ting 1. " coriaceous elliptic 

 stalked," stipules equally veined, (dry) b. keeled, ped. swelling 

 upwards.— ifi. vii. 34. Seem. J. of £. ii. t. 23. — St. ra.ther wavy, 

 branched below. Subm. 1. peUucid, often recurved ; upper 1. 

 often not coriaceous. Upper stip. large, persistent, nearly 5 as 

 long as the peduncle. l)ry & with 3 ridges on the back. — 

 Lakes near Brandon Moxmtain,- Kerrj'. Loch Ascog, Bute. 

 River Tay, Perth. P. VH.,Y1IL S. L 



*• i. aU submersed, membranous, lanceolate or broader; stipuies 



free. 



9. P. lucens (L.) ; I. pellucid oval or lanceolate stalked mi- 

 nutely denticulate and cuspidate, stip. winged, fr. blunt on the 

 back and slightly keeled T^hen h6^,pedmicle swelling upicards, 

 spikes cylindrical densely flowered. — B. B. 376. iJ. vii. 36. — 

 All the stipules have two prominent wings on their back. Spikes 



r2 



