74 



Bennett : Notes on the Potaniogetons. 



In the case of a bacterial epidemic it is of primary import- 

 ance to prevent, as far as possible, the dead parts of affected 

 plants from decaying- on the ground, otherwise the germs 

 become liberated in the soil, where they are capable of remaining 

 for an almost indefinite period of time, and a recurrence of 

 the disease is practically certain. 



Burning is the only safe method of disposing of infected 

 plants, and sterilisation of the soil where such plants have 

 g-rown is a wise precaution to take. 



NOTES ON THE POTAMOQETONS 



OF SIR J. E. SMITH'S HERBARIUM WHERE 

 LOCALISED FROM YORKSHIRE. 



ARTHUR BENNETT, F.L.S., 

 Croydon. 



Finding that Smith's specimens give at least two species not on 

 record for the county of York, I thought it would be of interest 

 to Yorkshire botanists to put in print a few notes respecting 

 them, because, although mentioned in Top. Bot., ed. 2, 1883 

 (from my notes), no explanation is given, or acutifolius named 

 as an accepted Yorkshire species in either of the three floras 

 that treat of the county, i.e.. Baker's 'North Yorkshire,' Lees' 

 ' West Yorkshire,' or Robinson's 'East Riding Flora.' I take 

 the specimens as they occur in his herbarium. 



'P. heterophyllus Schreb., Lips. Sheet 5. 



P. paltistre Teesdale. 



No. I. Ditches in the marshes near Beverley. Mr. Teesdale, 

 1794. No. 10.' Correct. 



Two other specimens so named are P. angiistifolius Bertch 

 and Presl. (Zisii). This adds another species to Mr. Robinson's 

 ' Flora of the East Riding-,' V.C. 61. (I possess a specimen of 

 this gathered by Mr. and Mrs. Cotton, June 1884, from Scar- 

 borough Mere, V.C. 62.) An addition to North Yorkshire. 

 So far as I know there is no record for Zisn in Yorkshire. 



On a separate label ' P. palnstre foliis inferioribus submersis 

 lanceolati membranaceous sessilibus superioribusovali-lanceolatis 

 petiolatis coriaceus natantibus. Mr. Teesdale. In ditches in the 

 marshes near Beverley. 



See P. fliiitans, Hoff. Fl. Germ., which, however, it cannot 

 be.' 



Naturalist, 



