REPORT FOR 1910. 
599 
I see praelongus in the Canal. Perhaps Mr. Bennett can say if 
they are identical with Miss Palmer’s plants. — G. Claridge Druce. 
Potamogeioi gramineus, L., sensu lato. [ref. No. U. 5]. Borough 
Fen, Northants., July 19, 1910. Very abundant in one drive in the 
Fens, where this and other species are peculiarly restricted in their 
distribution. — G. Claridge Druce. The use of such ambiguous 
names was condemned by the Vienna Congress, and serves no 
good purpose. This plant looks like a form of F. nitens, Weber 
{Jieterophyllus x perfoliatus), from the short, shining, rather bright 
green, and sometimes semi-amplexicaul leaves. — Edward S. Mar- 
shall. Potamogeton gramineus, var. heterophyllus, Fr. — P. Gr.aeb- 
NER. Mr. Marshall is not quite consistent, for in the works for 
which he is responsible he retains many names which are equally 
ambiguous. Wide and sweeping indeed would be the changes 
in nomenclature if he pressed his point to the logical conclusion ; 
it will be observed that the continental authorities most in touch 
with the Vienna Actes do not suggest such a course ; and indeed 
deliberately ignore it. — G. Claridge Druce. 
X Potamogeton Cooperi, Fryer {=P. Jacksoni, Lees). River 
Wharfe, near "llkley, v.-c. 64, York, Mid-west, altitude 230 feet, 
August 19 10. Named by Mr. Arthur Bennett. So far as I have 
observed, no other species occur along with it in the locality. It 
is fairly abundant in the river from Ilkley downwards, but flowers 
are only sparingly produced. Mr. Bennett and Mr. F. A. Lees 
inform me that it is the same plant as occurs in a small pool on 
Linton Common, near Wetherby, liable to be overflowed when the 
River Wharfe is in flood. It was first found there by Mr. J. 
Jackson, about the year 1880. See ‘ Bot. Record Club Rep.,’ 
pp. 150-1, 1882 (1880). — A. Wilson. Correct. — P. Graebner. 
Rightly named. — Arthur Bennett. 
Potamogeton pusillns, L. [ref. No. 4311]. Peakirk, Noithants., 
September igio. Plentiful and fruiting freely in one of the numer- 
ous fen ditches. — G. Claridge Druce. 
Potamogeton • Very brackish ditch, Biograve Level, 
Norfolk, August 1909.— C. E.' Moss. P. pusillns, var. tenuissimus, 
Mert. and Koch.— A. Bennett. This is very like my sheet of 
Mr. Salmon’s P. rntilus from Rye, E. Sussex, which unfortunately 
is in flower only. I have no description of that species handy ; 
the fruit here is smaller and more regularly orbicular-ovate than 
in ordinary P. pusillus, and very unlike that of P. trichoides.— 
Edward S. Marshall. No ripe fruit on my example, but foliage 
indicates pusillus. Habit reminds one of P. rutilus ; but the leaf- 
apex of that is more acuminate. — C. E. Salmon. Potamogeton 
