NOTES* ON BEITISH POTAMOGETONS 11 



f. pygmcBoides Hagst. Loch Lairing, 1600 ft. alt., M. Perth, 

 W. F. Miller. 



*P.gessnacensis Fischer (p. 192). P.natans Xpolygonifolius; var. 

 JRichtsfeldii Fischer=f. hiberniciis Hagstr. Upper Lake, Killarney, 

 1874, a. M. Barrington : I su^Dpose the " Long Range, Killarney 

 (1888), Scully''' would also be so named. Fryer called it "a f. of 

 jluitans,'''' but in this I do not concur. Then there is the " Balli- 

 nahinch River, Co. Galway (1871), A. G. More'' plant: this I 

 consider a state of natans. Fryer's splendid series of natans, dried 

 in each month of the year, shows clearly that many forms called 

 h3^brids are merely states of this species. 



P. POLTGOXiFOLius Pourr. (p. 175). Sweden to S. Helsingland, 

 c. 61° 30' n. lat. ; Norway at Melo, m"" 50' n. lat. (Blytt) ; Finland, 

 Aland, 60° 20' n. lat. {Hjelt) ; Scotland, Shetlands {Beehy). 



Here we have a species that is not abundant in Scandinavia, hence 

 we get no new varieties ; yet in leafage no species is more variable. 

 From a small form with leaves 20 mm. X 10 mm. to a large one 

 130 mm. X 48 mm., and a deep water state 180 mm. X 6 mm., every 

 possible gradation can be found. Of f . cancellatus Fryer — a Shetland 

 plant which Beeby was inclined to put as a hybrid — Hagstrom 

 remarks " if not a hybrid it might be considered a f . of v. lanci- 

 folius.'" 



P. sPARGANiFOLius Lacstad. (p. 217). This Hagstrom considers 

 a hybrid — gramineus L. X natans L. — and localizes " Shobden Marsh, 

 Heref. 89, A. Ley; Surre}^ A. Bennett, 86; York, Ripon, 80, 

 JSTicTiolson ; and a dubious f . from Caithness, E. S. Marshall. The 

 Surrey plant I have not yet traced ; the Hereford one is simply a state 

 of 7iatans (as Dr. Hagstrom himself named a sjDecimen I have) and so 

 is the one from Ripon. The Irish plant presents a more difficult 

 problem. Hagstrom puts it under sparganifolius (i. e. Kirlcii Sjnne) 

 without any hesitation ; Babington considered it absolutely agreed 

 with Laestadius's plant ; Syme, Fryer and I dissented ; a study of 

 the plant in situ is required. 



P. FLUITANS Roth. (p. 238). Hagstrom proposes another name — • 

 P. sterilis — for this much discussed plant. This seems unnecessary : 

 Roth's name should be retained for the hybrid, and use P. nodosus 

 Pourr. (as the author does) or P. americanus Ch. & Schlech., which 

 latter is certain for the plant, which is very ably discussed. 



P. COLORATUS Vahl " in Hornemann, Flora Danica, 1813, t. 1449" 

 (p. 178). " M. Vahl et Hofman-Bang primi plantam . . . detexerunt, 

 sed Hornemann nominis autor est " (Lange, Nomencl. Fl. Dan. 

 132). Sweden, Gothland at c. 57° n. lat. Not on record for Norway 

 or Finland. Scotland to 56° 30' n. lat. (v.c. 103). 



f . grandifolius leaves, 70-80 x 30-45 mm. The Cambridgeshire 

 fens produce it with leaves 150 mm. x 50 mm. on boulder clay; .in 

 Herefordshire specimens they are 150 mm. X 55 mm. 



*P. ANGLTCUS Hagst. = P. coloratusx polygonifoUiis (p. 180). 

 " Although coloratus and polygonifolius are so closely connected one 

 to another, yet nobody has observed any crossing between them. Some 

 specimens from Woking Heath, in Surrey, England, gathered by 

 Ar. Bennett in 1881, however, seem to me in all probability to be such 



