264 THE SYNONYMY OF POTAMOGETON ZIZII KOTH. 



Dr. Celakovsky poiuts out that Presl's description is imperfect, 

 while that of Mertens and Koch is very clear. There exists no 

 specimen of Presl's plant at either of the jjublic herbaria in Prague. 

 No doubt, as the name is taken up in Opiz ' Bahmens phanerog. 

 und cryptogam. Gewachse,' 1823, p. 23, in Kosteletzky's ' Clavis 

 anal. Floram Bohemiae phanerog.,' 1824, p. 24, and again by 

 Fieber in 1838, it does a^Dply to that form of Zizii which is called 

 elomjatus. Tliis matter, however, only affects the plant uhen 7tamed 

 as a species. 



Reichenbach, in liis ' Icones Fl. Germ, et Helv.,' vol. vii., 

 mentions that it is the P. Imiceolatus of Wolfgang. I can find no 

 publication of this name by Wolfgang ; it probably will be found in 

 his MS. monograph of tlie genus in the Moscow Society's Library, 

 which Trautvetter, in liis ' FL Ross. Fontes,' 1880, says he has 

 not seen. 



These refer to the plant as a f^pecics. As a variety it has been 

 placed under both lucens and heterophyllus ; apparently the earliest 

 date to which it can be traced as a variety is in Pohl's ' Tentamen 

 Flora Bohemioe,' 1810, p. 157, where it occurs as " P. lucens /?. fol. 

 angustioribus " ; if this is held inadmissible as a name, the next 

 seems to be P. lucens ft. iiitens (Willd. sp. ined.), Chamisso, in 

 Adnot. ad Fl. BeroL, p. G, 1815. There is a specimen of this in 

 the General Herbarium at Berlin, which is clearly Zizii ! Chamisso 

 remarks on this, "Varietas nee species." 



Following this there is what I believe to be a reference to P. 

 Zizii in Gray's Nat. Arrangement of Brit. Plants, v. 2, 1821, p. 34, 

 where 2b ^^ (3. mujicstifolius" is given under Lucens, with a reference 

 to Pay's '* P. folio angusto, pellucido, fere gramineo, Syn. 148, 3." 

 Ray's name is quoted under lucens in Sir J. E. Smith's Fl. Brit. 

 1800, p. 195, and under lieterophyllus in his Engl. Flora, ed. 2, 

 vol. i. p. 230, in both cases with a mark of doubt. There seems to 

 me no doubt that the Engl. Bot. fig. t. 376 of luceiis is decidedly 

 nearer Zizii. Chamisso notes this, saying, " P. lucetiSy Engl. Bot. 

 t. 376, est P. Proteus lucens forma Zizii vergens." 



Under heterophyllus it seems to have been published under two 

 names in the same year (1823) by Mertens and Koch, in Rohling's 

 Deutsch. FL vol. i. p. 845, as var. latifolius; and in Schlechtendal's 

 Fl. Bevol. p. 116, as var. fluviatilis. Rohling's Flora shghtly 

 precedes Schlechtendal's in date. 



Coming to later times, there is in Blytt's * Norges Flora,' 1861, 

 p. 364, a '^lucens? /3. angustifolius,'' which the author thought 

 might be the P. longi/olius of Gay. By the kindness of Prof. A. 

 Blytt, I have an original specimen of the plant of his father, and 

 can say it is not the plant of Gay, but is a Zizii form, corresponding 

 exactly with the " P. lucescens " of Dr. Tiselius, of which the author 

 says, " sine dubio forma P. Zizii Met. K." 



P. Zizii is widely spread over the world; in Europe from Nor- 

 way ! to Hungary ! (or perhaps Italy) ; in Asia rare ; in Africa very 

 rare ; and in N. America occurring from 57° N. lat. (-/. ^f. Macowil), 

 south to Cuba (C. Wriyht !), and Florida [Torrey herh.fule Movony). 



