FORMS OF POTAMOGETON NEW TO BRITAIN 175 



9. P. pr^longus Wulf. I have as yet seen no British speci- 

 mens of the extreme states of this species, i.e. brevifolius Celak., or 

 the Swedish plant with leaves twelve inches long ! — f . elegans Tis. ; 

 but a very narrow-leaved form (eight inches long) occurs in Cauld- 

 shiels Loch, Roxburgh (A. Brotherston), and in Kinardlochy Loch, 

 alt. 1250 ft., in Mid Perth (W. F. Miller). This I take to be the 

 11 var. (3 foliis angustioribus ■' of Hooker's Brit. Fl. ed. 3, 77 (1835), 

 judging from specimens in the Kew Herbarium. 



10. P. Friesii Rupr. x P. acutifolius Link ? A specimen from 

 Wretton Fen, West Norfolk (Boswell herbarium ex Mr. F. J. Han- 

 bury), is probably the above, but the material I possess is poor, and 

 it must be gathered and studied in situ. I believe about twenty-five 

 acres of the fen are still existent, as this was awarded to the poor 

 for turf-cutting at the enclosure. 



11. P. undulatus Wolfgang in Roem. & Schult. Syst. Veg. 

 Mant. iii. 360 (1827). For a note on this (the true plant) see Ann. 

 Scott. Nat. Hist., April, 1907, 104. 



12. P. alpinus Balbis X P. pr^elongus Wulf. ? In the Canal 

 Odiharn, North Hants, 27, 6, 1880 (Miss Charlotte E. Palmer). I 

 wrote to Miss Palmer respecting these specimens, and she kindly 

 sent me specimens in 1901, H gathered within one hundred yards of 

 those in 1880." These proved to be alpinus, but the flowers seemed 

 all sterile. I could not find a fruit formed on any of the spikes, yet 

 alpinus is one that fruits freely. This, of course, points to a state 

 of alpinus rather than a hybrid, but the 1880 specimens are de- 

 cidedly different in habit and leaf-structure. Miss Palmer name3 

 natans, perfoliatus in plenty, and pectinatus as growing in the canal 

 near, and suggests " alpinus x perfoliatus," but I do not think this 

 can be so. I am not aware that this hybrid has occurred : neither 

 do I recollect ever having seen the two species in juxtaposition. 

 There is no record of P. prcelongus from the canal in Surrey, and it 

 is not given by Mr. Townsend for Hants. It is a species not 

 recorded for the southern counties of England, though I should 

 expect it to occur in some of the larger ponds of Hants (i. e. Fleet 

 or Sowley, &c). The early date is ,not against it, as I have speci- 

 mens from Anglesea with ripe fruit gathered in June, In the 

 specimens the flowers are dropping off at this early date (in June). 



13. P. alpinus Balb. var. S lacustris Marss. " Caule inter- 

 nodiisque valde elongatis : foliis natantibus minimis ssepe deficienti- 

 bus, submersus augustis elongato- vel lineari-lanceolatis undulatis" 

 (Marsson, Fl. Neu-Vorpomm. und Rugen, 490 (1869) ). (Herb. 



Buchanan !). 



Hab. Lunan Burn, East Perth, July, 1882 (J. Sturrock). 

 The typical plant grows in the same burn, and was gathered at 

 the same date. 



14. P. upsaliensis Tiselius in Bot. Notiser, 1884, 15. P. deci- 

 pieris Nolte in part ex Asch. & Graebn. op. cit. 832. One specimen 

 sent me by the late Mr. Sturrock from " the Earn above Forteviot, 

 West Perth, 18. 7. 1881. leg. Dr. Buchanan White'': it should be 

 searched for by Perth botanists. 



