81. POTAMACE.E. 345 
1131. Potamogeton rufescens, Schrad. 
Provinces 1 to 17. Native. 
Lat. 50—59. Cornwall? Sussex, Kent. — Isla, Caithness. 
Zones 123. Tyne to 500 yards. 
Census 17 26 388. Ireland 9. British type of distribution. 
Europe - ita - aus ger fra cha net den got nor swe lap. 
Russia ---3 2. Himalaya. Siberia. Davuria. 
— Iceland; Lindsay flo. Greenland. America. Columbia. 
1182. Potamogeton natans, Linn. 
Provinces 1 to 15, or all by safe and unsafe records. Native. 
Lat. 50—58 or 61. Cornwall, Wight, Kent. — Hebrides? Shetl.? 
Zones 123. Low grounds. Confused with ‘ polygonifolius.’ 
Census 15 32 ? Ireland 12. Bvritish type of distribution. 
Europe all, except Finmark. 
Russia 6-4 321. India. Siberia. Davuria. 
Algeria. Madeira. Azores? — Faroe. Iceland. America. Ool. 
1132 (1133). Potamogeton polygonifolius, Pourr. 
Provinces all. Native. Often mislabelled ‘ natans.’ 
Lat. 50—61. Cornwall, Wight, Kent. — Orkney, Shetland. 
Zones 1234. Lakes to 590 yards. Highlands to 530 yards. 
Census 18 384 65. Ireland 11. British type of distribution. 
Europe spa ita - aus ger fra cha net den got nor swe. 
Russia --- 3. Siberia. 
Algeria. Canaries? Azores! — America. 
1132 (1134). Potamogeton plantagineus, Ducros. 
Provinces-234-678-101112-14-16. Native. 
Lat. 50—57. Wight, Hants, Kent. — Arran, Argyle. 
Zones 123. Humber to 150 yards. Area ill ascertained. 
Census 11 15 22. Ireland 9. English-british type. 
Europe - ita - aus ger fra cha net den. N.B. Apparently re- 
stricted to Europe; but this and ‘ polygonifolius’ have been 
much confused with each other and with ‘ natans.’ 
2x 
