294 NOTES ON POTAMOGETONS, 
Polypodium lobatum Agaricus lactifluus 
cristatum campestris 
Polytrichum commune verrucosus 
Lichen candelarius Boletus versicolor 
capreatus 
resupinatus uteus 
sylvaticus Phallu mpudicus 
pyxidatus Clavaria pistillaris — 
rangiferinus ophioglossoides 
Tremella Nostoc Lycoperdon Tuber 
Agaricus Chantarellus Bovista 
integer 
NOTES ON POTAMOGETONS. 
By Arruur Bennett, F.L.S. 
(Continued from p. 134.) 
Tue nomenclature of some of the species of Potamogeton is 
difficult to deal with satisfactorily ; I propose here to discuss P. 
tenuifolius. Three distinct plants have been so nam d :—P. tenui- 
Jolius Rafinesque, Med. Rep. 409 (1811); P. tenuifolius H. B. K. Nov. 
G i. 297 (1815); P. tenuifolius Philippi, ined., in herb. 
The doubt about Rafinesque’s plant renders it inadmissible to 
adopt Philippi’s MS. name, although the plant to which he gives it 
1s a good species. I therefore propose to name it P. Aschersonii,* 
_ Its affinity is with P, pusillus L. and P. Berteroanus Philippi in 
<a erably in its leaves, 
but so many of the South American specimens of the pusillus group 
are badly preserved, that without ‘soaking out” it is difficult to 
determine their true character. 
I refer to it the following gatherings :—Chili, Philippi! Val- 
Paraiso, Bridges! Argentina, Hieronymus | Tweedie!? Uruguay, 
Columbia, Jameson ! Brazil, Gardner! Proy. Rio de 
Janeiro, Glaziou! 
- Aschersonii mihi. P, tenuifolius Philippi ined. Stems 
slender, terete, 6-18 in. long, branched, especially in the lower 
half; rarely with long (8-4 in.) internodes. Leaves variable, 
*I have ascertained from Prof, Ascherson that he has t named the 
plant, as I thought he might have don tas 
e, for the Fl. Brasiliensis, 
