198 THE JOURNAL OF BOTANY 



6 mm. long, 5*5 mm. greatest breadth when flattened, terminal 

 lobe 1-25 mm. long by 4-75 mm. broad. Column 3 mm. long, foot 

 8-5 mm. Anther-cap rounded, poUinia deep yellow, cohering in 

 pairs. Mr. Sparkes says : •* Sometimes, usually early in the day it 

 is very sweet-scented, later no trace of scent is to be perceived." 



Nearly allied to D. gracilicaule F. Muell., but apparently a 

 larger plant with stouter more fusiform stems, cream-coloured 

 flowers and sepals not spotted, more pointed perianth-leaves, and 

 narrower petals. The lip also has shorter lateral lobes, and the 

 disc bears a single, not a trilamellate keel. D. gracilicnule has a 

 more southern subtropical distribution, occurring in New South 

 Wales and as far north as Moreton Bay, in Queensland ; the present 

 species is well within the tropics. 



I). Jonesii is evidently closely allied to, and may be identical 

 with, D. gracUicauU var. Howeamon Maiden (in Proc. Linn. Soc. 

 N. S. Wales, xxiv [errore xxv] , 1899, 382), from Lord Howe Island. 

 This agrees in the stouter stem and the colour of the flowers, but 

 the author makes no mention of any differences in form and size of 

 sepals, petals, and lip. 



Hab. Near Geraldton, Johnstone Eiver, North-east Queensland, 

 A. Owen Jones, Esq., J. P. 



Flowered by Mr. J. Sparkes at Ewhurst, Surrey, January, 1901. 



NOTES ON POTAMOGETON. 

 By Arthur Bennett, F.L.S. 



(Continued from Journ. Bot. 1900, p. 130.) 



Potamogeton fluitans Roth. The following extract from Roth's 

 Catalecta Botanica (fasc. 1, p. 31, 1797) will show that Schreber's 

 specimens in the Munich Herbarmm are, as I supposed, the plant of 

 Roth: *^ Potamogeton Jill itans foliis inferioribus longissimis, lanceo- 

 latis, acuminatis, membranaceis ; superioribus ovali-lanceolatis, 

 cariaceis omnibus petiolatis. Pioth, Fl. Germ. torn. 1, pag. 72; 

 tom. 2, pars 1, pag. 202, no. 2. Prope Erlnngam etiam obser- 

 vavit 111. Praes. de Schreber.'" 



To the best of my belief these specimens represent the plant 

 accepted by European botanists as the plant of Roth. 



P. poLYGONiFOLius Pour. In his account of this plant (as P. 

 ohlongus Viv.) in Linnaea, ii. 216 (1827), Chamisso says: " Hujus 

 loci forsitan est : Potamogeton de St. Pierre Miguelon pres Terre- 

 neuve in Herb. Brongniart, sed major." Since that time I know 

 of no record of the species from the American continent. Specimens 

 allied to it occur in Chili!, Uruguay!, Argentina!, &c., but they 

 are not the same. I have not seen Brongniart's specimen, and 

 Dr. Morong does not include polygunifoUus in his N. American 

 XaiadacecB ; but, from the occurrence of Calluna in Nova Scotia and 

 Newfoundland, I have been expecting to hear of its occurrence in 

 Canada. Prof. Macoun has now sent me specimens from Sable 



