1921-22.] BOTANICAL SOCIETY OF EDINBURGH 115 



deep, in a loch almost at sea-level, Bay of Islands, Loch 

 of Harray, Harray, Mainland, 2nd August 1920, H. H. 

 Johnston. Native. Rare. Plants in flower. Peduncles 

 4-5 inches long, with flower spikes f-1 inch long. My 

 specimen and the specimens collected at the same time by 

 Prebendary R. J. Burdon and Dr. G. Claridge Druce, in 

 my company, grew sparingly in the channel between Ling 

 Holm and the small island immediately to the north of it. 

 With reference to my specimen, Mr. Arthur Bennett, in a 

 note dated 11th November 1920, writes as follows: — "A 

 very peculiar plant. If NITENS it will come under d. 

 SUBGRAMINEUS, Hagstrdm, form stenobasis, Hagstrom, 

 ' Critical Researches on Potamogeton,' p. 224 (1916) ; seems 

 to be recorded only from Sjogesater in Sweden. It is 

 the nearest form to heterophyllus." See "Bot. Exch. 

 Club Report for 1872-1874," p. 40 (1875), where under 

 P. NITENS, Weher, Dr. J. T. I. B. Boswell writes as follows : 

 — " A single specimen gathered by me in the Bay of Islands, 

 Upper Loch of Stenness [the Loch of Harray is meant — H, 

 H. Johnston], August 1873"; and, with reference to Dr. 

 Boswell's specimen, Mr. Arthur Bennett, in " Scot. Nat.," 

 No. i, new series, p. 24 (July 1883), writes as follows : — 

 " I believe this is correct ; it is of course widely diflerent 

 from the curvifolius, Ha it., and comes between Weber's 

 type and var. latifoUus, Tis. ! " See also " Bot. Exch. Club 

 Secretary's Report for 1920," p. 151 (September 1921). 



Potamogeton polygonifolius, Pourr., var. cordifolius, 

 Asch. et Graebn. {fide Arthur Bennett). — Mud at bottom 

 of water in a ditch in a peat moss, Kingsdale, Firth, 

 Mainland, 15th September 1880, H. H. Johnston. Native. 

 Plants in fruit. A new record for this variety for H. C. 

 Watson's county No. Ill Orkney. 



IsOETES LACUSTRis, Linn, (name confirmed by Arthur 

 Bennett). — Mud at bottom of water, 7 feet deep, in a loch, 

 328 feet above sea-level, Peerie Water, Rousay, 22nd 

 August 1921, H. H. Johnston. Native. Common in the 

 deepest parts of the loch where the bottom is muddy. 

 Plants in full fructification, growing close together in dense 

 tufts, and wholly submerged in water. Leaves suberect, 

 or recurved, subulate, roundish-quadrangular, dark green, 

 with four longitudinal jointed tubes. Larger spores globose, 



