THE FLORA OF HALIFAX. II3 



Sagittaria sagittifolia, L. — 58. Arrow-head. 

 Native. English type. P. July-August. 

 1862. Halifax canal. — Midi's Flora. 

 1867. In the canal near Salterhebble. — /. Walker. 

 Still in the same locality, its only station. 



NAIADAOEiE. 



[Triglochin palustre, L.— no. 



Unknown. British type. P. July. 

 No record from the parish, though a specimen from Shedden 



Clough (west of Stansfield Moor), is in Herb. Leyland. 

 It might be found in marshy ground, and there are many 

 likely localities for it.] 



Potamogeton natans, L.— 100. Pondweed. 



Native. British type. P. July-September. 



[Ditches, Norland Moor. — Herb. Leyland.'] 



[1867. Ogden cloughs. — /. Walker.] 



These and other records of the moorland pondweed refer to 

 the next species. P. natans is a lowland plant, only likely 

 to occur here between Luddenden Foot and Brighouse ; 

 it is only known to me at Tag Lock, Elland (200 ft.) 

 where it is abundant towards the eastern end. 



Potamogeton polygonifolius, Pour.— 107. Pondweed. 

 Native. British type. P. July-September. 



1 84 1 . Barkisland Moor edge, above Ripponden — Herb S.K. 



1888. — Todmorden [A. Stansfield) ; Hebden Valley (F. A. 

 Lees) ; Norland Moor. — Lees' Flora. 



Common on or near the moors in streams, ditches and 

 shallow pools, above 500 ft. ; Norland Stream, Rishworth 

 moors, Erringden, Ogden, Luddenden, Widdop, Stans- 

 field moors, &c. 



Potamogeton crispus, L. — 94. Curled Pondweed. 

 Native. British type. P. July-August. 

 Near Carr Mill (Hebden Bridge). — Herb. Gibson. 

 1862. Halifax Canal ; river Calder. — MialVs Flora. 

 Infrequent : Tag Lock, canal at Salterhebble, mill dam 

 at West Vale. 

 Potamogeton obtusifolius, Mert. and Koch.— 54. 

 Native, English type. P. July-September. 



