NOTES ON PONDWEEDS. 



297 



also apparent that the new quadrinomial nomenclature is not free 

 from complications : here are a few names from Mr, Stewart's 

 book, with their equivalents in what Mr, Britton wants us to cite 

 as B.S.P. :— 



Stewart, 

 Glaucium flavum Crantz (G. 



luteum Scop.). 

 Nasturtium palustre (Willd.) De 



Candolle. 

 sylvestre B. Brown. 



B.S.P. 



Glaucium luteum, Scop. 



Nasturtium palustre, (L.), DC. 



sylvestre, (L.), E. Br. 

 Barbarea precox, (Smith), R. Br. Barbarea pnecox R. Brown. 



Arabia hirsuta, (L.), Scop. 

 Sisymbrium Alliaria, Scop. 



Thaliana, (L.),Gay 



Scnebiera Coronopus, (L.), Poir 



Arabis hirsuta (Linn.) R. Brown. 

 Sisymbrium alliaria Linn. 



thalianum (Linn.) 



Gaud. 

 Senebiera coronopus (Gaert.) 



Poiret. 



Mr. Stewart also gives " Lepidium Smithii (Linn.) Hooker," as 

 to which I would only remark that this species was first described 

 by Hooker in 1835,* nearly eighty years after the death of Linmeus. 



James Britten. 



NOTES ON PONDWEEDS. 



By Alfred Fryer. 



POTAMOGETON FLABELLATUS Bab. Rootstock stout, tllbcrOUS, 



with far-creeping stolons. Stem stout, round or slightly two edged, 

 much branched from the base when rising from a tuber or old root- 

 stock, but usually simple below when springing from a newly- 

 produced stolon, ultimately much branched above, with the branches 

 spreading on the surface of the water like a fan. Leaves all 

 similar, submerged, alternate, linear, flat, with the lower ^ part 

 united to the stipule, and so forming a sheathing petiole, which is 

 elongated into an obtuse scarious ligule, free at its apex. Lamina 

 of the lower leaves broadly linear, abruptly cuspidate or acute, or 

 rarely rounded and slightly concave or hooded at the tip, 4-6 in. 

 long by | in. wide, 3-5-ribbed, with transverse veins, decayed on the 

 fertile stems at the time of flowering ; sheathing petiole £-£ as long 

 a « the lamina. Upper leaves 3-ribbed, narrowly linear, slightly 

 channelled, tapering to an acute or acuminate point. Peduncles 

 filiform, equal, lateral, or rarely terminal, exceeding the subtending 

 foliage, 2-4 or many times as long as the interrupted few-flowered 

 spike. Fruiting spike interrupted below or throughout its whole 

 length, or with the fruits more thickly clustered above. Fruit 



British Flora, ed. 3, 300. 



