376 NOTICES OF BOOKS. 



(M, J. Lloyd, of Nantes). This is a plant that has often been 

 reported as British, and as often contradicted, forms of jwlynoni- 

 folins, rufesceiis, and Zizii have been mistaken for it. There seems 

 no reason to doubt Mr. Fryer's specimens being the true plant ; 

 they agree well with specimens in the Berlin Herbarium determined 

 by Nolte and Chamisso, and with others in my own collection from 

 the herbarium of the late A. Braun. I am in hopes that Mr. 

 Fryer's specimens will fruit with him this year, when its identity 

 will be made quite certain. Indeed, the observations of my acute 

 friend almost make me feel sure ; i. e., ' its habit of growth is quite 

 different from P. natans, which grows in the same pit ; of that 

 roots come up freely, of this the roots strikes deep in the mud. 

 All the submerged leaves are alike, down to the very bottom, linear- 

 lanceolate. I can see its distinctiveness from deep-water forms of 

 polygoni/olms better now I have had a second look at it growing.' 

 There is one thing Mr. Fryer's specimens show, i. e., that the non- 

 branching of natavs, fluitans, and jwlijr/oiiifoliits has exceptions, and 

 in this I am supported by the opinion of my friend Eev. T. Morony 

 [Morong] of Mass., U.S.A., who writes that 'while the rule 



here, there are exceptions.' From the usual state of 



natans it differs in the upper leaves being gradually tapered into 

 the petiole, the midrib of much thicker consistence, the stipules 

 blunter, the siibmerycd leaves havhig lacinue, the fruits smaller and 

 more rounded. The submerged leaves, especially the young ones, 

 are of very thin texture. From all stages oi polygon Ifolins it differs 

 at once by the thick peduncles, larger flowers, and larger fi-uit. The 

 forms it is liable to be mistaken for are : — Of natans, the var. 

 prolixus of Fr. [P. serotinus Schrad.) ; and oi polyyoni/olius, the var. 

 pseudo-ftuita7is of Syme. The question of the phyllodia of P. natans 

 I have not yet been enabled to trace by growing specimens, but in 

 specimens of a form of pulyyonifolius, watched for five years (from 

 N. Wales, J. E. Griffith), I find the laminae to drop off, leaving the 

 petioles, which become nearly white, but in this state are persistent 

 to October and November. The leaves of this form assume a very 

 natans-\ike look, much like the specimens from ' Fleet Pond, N. 

 Hants,' in Mr. H. C. Watson's herbarium at Kew. It is this form 

 of polyt/onifolins that is often named natans! When in fruit, how- 

 ever, there is no difficulty. The distribution of P. Jiuitans Eoth. is 

 not yet worked out, the barren specimens in various herbaria being 

 extremely difficult to separate from some others " (pp. Ill, 112). 



" Potamogeton Griffithii A. Bennett. Lake, Llyn-an-afon, Car- 

 narvonshire. — J. E. Griffith. Several specimens of this plant. 

 I have had this growing with jn-alongus and rufescens for three 

 years ; its growth is much slower than either, and it does not die 

 down during the winter, the upper part only rotting away. By 

 this means I have assiu-ed myself that it is not proilungus ; at no 

 stage of its growth, from the first leaves to the flowering stage, can 

 it be mistaken for prcpdongus, on careful examination of its structure 

 (leaves, stem, &c.). I hope to succeed in getting my specimens to 

 fruit this year "' (p. 114). 



" Juncns nigritellus Don. Wet sand, near Wells, Norfolk, Sept. 



