12 THE JOURNAL OP BOTAIWT 



a bastard," p. 180. The specimens are simply a f. of polygonifolius 

 in dee])er water than usual on a heath ; the Avhole growth is of that 

 species and not colorafus. If other In^brids suggested rest on no better 

 ground than anglicns, I should say they are not to be depended upon. I 

 know the growth of coloratus well in the fens and broads of E. Anglia, 

 having seen hundreds in the living state. Hagstrom admits (p. 176) 

 that *' the stem-anatomy of the stem [of coloratus a^nd 2^ oli/g on if oli us] 

 is so much alike that it is practically useless for the distinction of the 

 species." Had he suggested that specimens from Shawley, Salop, 

 Nov. 1888, W. PJiillips, were coiglicus, I should hardly have con- 

 tested it ; the growth of the submerged leaves resembles that of 

 coloratus, and the floating leaves are thin, with the coloratus areo- 

 lation, yet the habit is that of polygonifolius. 



P. ALPINUS Balb. (p. 142). Sweden to Swedish Lapland; 

 Norway to 70° 25' n. lat. {Norman) ; Russian Sf Finnish Lapland, 

 08^ 43* {Hjelt) ; Scotland to Caithness, c. 59° n. lat. 



A very variable species ; Hagstrom does not adopt the names of 

 Fischer (in Ber. Bay. Bot. Ges. xi. 45, 1907), yet introduces two new 

 forms. Fischer has added to the difficulty of collating the varieties 

 In' giving a new interpretation of some of the old names. The 

 author places P. gracilis Wolf, under P. gramineus L. P. Druceii 

 he considers to be a hybrid — P. alpinusx nutans, as Mr. Druce first 

 suggested. 



P. LANCEOLATUS Sm. (p. 149) is regarded as undoubtedly a hybrid 

 — P. alpinus xpusillus. In this I do not concur : I consider it as 

 heterophyllus xpusillus. Hagstrom states that the submerged leaves 

 are " obtuse," but this is not the case : the}' are subacute ; I had the 

 plant growing for many years, and dried two hundred specimens and 

 distributed them so as to avoid despoiling the Welsh station. Every- 

 one who has grown or gathered alpinus knows the peculiar growth of 

 the rhizomes ; the}^ resemble no other British Potamogeton. The 

 roots of lanceolatus have nothing of alpinus in them, but they have 

 of heteropliyllus ; the floating leaves are not alj)inus either- in 

 chemical constitution or structure. A plant that has the chemical 

 nature of alpinus will show it in drying, and you can drive it back 

 by soaking again. 



For description and figures of the British plant, Hagstrom (p. 150) 

 refers to my pa})er in this Journal for 1881 (p. 05, t. 217). He 

 states tliat the ol)tuse apices of the submerged leaves remove it from 

 heteropliyllus : tliis is a mistake ; I have the plant dried from 

 cultivation from January' to August in ever}^ month, as well as the 

 autumn states, and they contradict this. 



P. iiETEROPiiVLrA'S Sclircb. (}). 204). The author places this 

 under P. gramiiieus L.. and remarks: "Although Linne in his short 

 tleserijition of this plant has not mentioned either floating or petioled 



leaves there is no I'cason to reject the Linnean name, and a 



mis-determination in Linne's herbarium does not alter the dignity of 

 the good old name." Why then does he use (p. 05) zoster if olitis 

 Schum. for compressus L. ? — There is nothing grass-like in hetero- 

 pliyllus, while in compressus there is the compressed stem, etc. The 

 specimen in ClifSort's herbarium is identical with Schumacher's 



