NAIDACEJE. 319 



NAIADACE^E. 



POTAMOGETON, L. 



662. P. natans, L. Floating Pondweed. 



Native ; iii streams and ponds. Rather common. June to Sep- 

 tember, 

 c. I. In a small tributary of the Notter, near Clapper Bridge. 

 D. Ill, Pond near Blaxton. Valley of the Tavy, between Lophill and 

 Denham Bridge. 

 IV. Chelson Meadow ; Shaugh Bridge ; Keys, Fl. iii. 248, 49. Pond 

 at Radford. Plym Valley, a little below Riverford. Wigvor 

 Down. [Pond by the Great Western Railway, near Chaddle- 

 wood, 1866 ; smce destroyed by alterations.] 

 V. In the Yealm tributary near Dalamore. 

 VI, Erme Valley, near Harford. 



663. P. polygonifolius, Pourret. Ohlong-haved Pondweed. 



Native ; in peaty pools and pits, in swamps, and by small streams. 

 Common. JMay to August, or later, 

 c. I. Viverdon Down. Pillaton Down. 



II. Bog in a little vale near Harrowbarrow, below Kingston Do^vn. 

 D. III. Swampy spot m a field in the vale just above Honicknowle. 

 IV. Bog on Derriford estate. Egg Buckland. 



V. Near Cholwichtown. Bog in an enclosure below Hanger Down. 

 VI , In boggy ground near the railway viaduct, Ivybridge ; Keys, Fl. 



iii. 249. Hanger Down. Damp spot m the Erme Valley, be- 

 tween Ivybridge and Harford ; and in this valley on Dartmoor, 

 growing in a deep pool, a form approachmg ysevxlo-fluitans, 

 Eng. Bot. ed. 3, but with fewer submerged leaves, 1876. 

 This is found mostly in the heathy and moory tracts. 



664. P. crispus, L. Curled. Pondweed. 



Native ; in streams. Very rare. August, September, 

 p. IV. In the stream at Shalaford, Egg Buckland, associated with 

 Ranunculus Drov.etii. 



VI. In a stream at Modbury, below the Kingsbridge Road. 



665. P. pusillus, L. Small Pondweed. 



Native ; in ponds and slow streams or ditches. Raj-e. July to 



September. 

 Pond at Pentillie. 



Chelson Meadow ; Keys, Fl. iii. 250. Pond at Radford. 

 Mill-stream, Bridgend. Blackpool ; probably extmct. 

 Ditch at Flete ; very small. 

 At least some of the Plymouth examples belong to var. h. tenuissimus. 



