200 THE JOURNAL OF BOTANY 



believe them to belong to the same form, which, I think, must be 

 referred to P. nitens, but in a form not found in Europe, as they 

 are probably produced by the var. Fiichanlsonii of perfoliatus, the 

 leaves being elongated in the same proportion, and so much longer 

 than any European form of nitens. Not only this, but one of 

 these specimens assumes the closely branched habit of that var. of 

 perfoliatus, with the dark and shining colour of nitens. 



The Rev. E. J. Hill sends me, from " St. Mary's River (in deep 

 water), often 6 ft. long; Sault Ste Marie, Michigan, U.S.A.," a 

 plant that I am unable to refer to any other than nitens Web. ; in 

 fact, it bears a remarkable resemblance to Dr. Scully's specimens 

 from Kerry, Ireland. Mr. Hill writes that it grows in deep water 

 with strong current. There are two or three spikes of flowers, and 

 these show the closed state usual in nitens. If Macoun's plant is a 

 product of the elongated leafed form of perfUiatus v. Piichanhonii 

 (often 4J in.), this will perhaps be the case with the intermediate 

 form, which seems absent in Europe. Forms approaching the 

 American have been sent so named, but I have not been able to 

 convince myself they are so. 



I have seen }ntens from the following localities in North America : 

 Wenham, Mass. (one specimen identical with some of Nolte's 

 Schleswig-Holstein specimens) ; Indian River, Millsboro', Dela- 

 ware, 1885, A. Conimaiis; and the stations already given from Rev. 

 E. J. Hill and Prof. Macoun. 



P. DiMORPHus Rafin. (P. Spirillus Tuck.) A very interesting 

 extension of the distribution of this species has been sent me by 

 the Rev. 0. Hagstrom ; specimens from Brazil gathered by Dr. 

 Lindman in 1892. In the United States, I do not know of it south 

 of Virginia (about 35° N. lat.), whence I have specimens ; but the 

 allied species, F. diversif alius Rafin. (P. hijbridus Michx.), ranges 

 soath to San Luis Potosi, Mexico ! (25° N. lat.) on the west, and to 

 Cuba ! on the east of the continent. It is possible that when the 

 intervening countries are more thoroughly examined one or the 

 other of these species will be discovered. In the British Museum 

 Herbarium is a specimen, " Bahia Blanca. B. Ayres, Argentina, 

 1884. M. G. Mansel, R.N.," which is allied to P. amplifolius 

 Tuck., but the lower (middle) leaves are tapering into the petiole. 

 Further specimens would perhaps connect the two, and prove 

 another interesting extension. P. amplifolius occurs south to 

 Forida, Chapman, 1844 ! (as P. natans). 



P. AcuTiFOLius Link. In Schreber's herbarium at Munich are 

 specimens of this plant labelled "Lancaster, Pennsylvania, Muhlen- 

 berg." I asked Dr. Morong his opinion of this ; he replied that he 

 thought there was a mistake in the label. He wrote further : " Dr. 

 Porter, of Lafayette College, has been all over that region, and two 

 keen- sighted students of ours have been fishing in these waters for 

 the last two years ; none of them has found this species, or my 

 Hillii, P. zosterifolins occurs in the region, as well as further 

 north." There is no question that the specimen is acutifolitis, and, 

 although perhaps some transference of labels may have taken 

 place, it would be well for American botanists to keep it in mind. 



