28 The Scottish Naturalist. 



extent ; but I prefer a middle course to making species ap 

 libitum" 



My esteemed correspondent has kindly sent me the following 

 description of the plant : — 



11 Stem much branched, 18 in. to 3 ft. long; leaves ij in. to 2 in. 

 long, J in. broad, with the secondary veins indistinct. Stipules 

 \ in., blunt. Peduncles, 1 in. to 2 J- in. long ; spike, \ in., very 

 sparingly flowered ; sepals, thick. 



" A very elegant sub-species of pusillus, L., with somewhat the 

 habit of obtusi/olius, M. et K. Quite distinct from anything seen 

 from Europe or N. America. Named after the discoverer, who 

 has so successfully worked at the aquatic plants of Perthshire and 

 Forfarshire." 



It may be of interest to note that " winter buds," or " gemmae,'' 

 occur freely on this plant. These are " hardened masses like 

 leaves agglomerated together," which fall off in the autumn and 

 become plants the next year. I have observed them also on P. 

 crispus, P. mucronatus, the ordinary form of P. pusillus and P. 

 obtusifolius, on the latter of which, in Marlee Loch, I found them 

 on almost every shoot in September last. 



Same date. — Lunan Burn. 

 P. heterophyllus, Schreb. 



{P. lofigipedunculatus, Merat, Flora Paris) ; fide Bennett. 



This plant has larger submerged leaves than the typical heter- 

 ophyllus, no floating leaves, and very long peduncles. Found in 

 the stream at the head of Marlee Loch. 



Aug. 8th. — Loch Bog or Stormont Loch, near Rosemount 



Station, Blairgowrie. 

 P. pusillus, L. 



A very delicate form, with beautiful light green leaves, and short 

 peduncles ; fruits freely. Mr. Bennett is of opinion that this may 

 be P. Berchtoldi Fieber. It also occurs in Marlee Loch. 



August nth. — Lunan Burn. 



In the burn immediately below the point where it leaves Cluny 

 Loch at Tullynedie Bridge, there is a fine bed of another most 

 interesting Potamogeton, regarding which Mr. Bennett writes : — 

 " Certainly nearer nitens than heterophyllus. These cannot be 

 labelled nitens or heterophyllus ; hence, as Dr. Tiselius justly 

 observes, ' Why should they not have a name 1 ' And your 

 specimens will compare with his form ' k and h ' of borealis, Tis." 



Like nitens, this plant is occasionally stoloniferous even from 

 the upper axils, which I have not observed in nitens. 



