



t 



of the 



'£ 



353 



- 



rather slender, short, more or less scarious at ihe margins, acutish. 

 Peduncles a little thickened, rather more than twice as long as 

 the spikes, but elongated in the deep water forms, and occurring 

 10 inches and more in length. Spikes slender, densely flowered. 

 Nutlets small, somewhat rounded, obliquely obovate, lunate, 3- 

 carinate, the keels a little prominent and acutish above, the sides 

 convex, the face produced above and apiculate with the very 

 short style. Exocarp rather thin. Putamen thickish, but not 

 hard. Seed curved-uncinate. The exocarp being removed, the 

 sides appear rather suddenly hollowed, at the middle, toward the 

 face. Agrees with the European specimens in habit, in the 

 leaves, and the fruit. P 



the present species by its large size, and the different habit in- 

 duced by its nearly simple branches ; and its dentate-cristate fruit 

 separates it from every described European species. The leaves 

 of P. gmmhieus often approach a sublinear form, but the proper 

 affinity of the species is with P. nit ens and P. lucens, and not 

 with the Graminifolii, or truly linear-leaved section. 



Potamogeton compressus, (L.): caule alato-complanato ramo- 

 sissimo ; foliis omnibus submersis saturate viridibus membrana- 

 ceis linearibus versus apicem sensim vix attennatis apice breviter 

 acuminatis cuspidatis, basi hand attenuatis sessilibus, 3-5-nervi- 

 bns, iufimis brevioribus multinervibus ; stipulis 1 ingui form i bus 

 pellucidis acuminatis demnm laceris ; pedunculis compressis spicis 

 I cylindricis continuis hand duplo longioribus ; fructibus recent i baa 



j obovato-oblongis, stylo apicali leviter recurvo-rostratis, dorso 



latiore acute carinato sinuato-dentato, carinis lateralibus obsoletis, 

 facie obtusa. P. compressus, L. Suee* ft. 203, e Fr. NoviL, p. 

 45. Torr. ! FL U. 8., p. 198. Koch. Syn., p. 676. Beck. ! 

 Rot., p. 386. A. Or. t Man. Bot., p. 456. Wood Bot, p. 526. 

 F. zostertvfolins, Schttm. Eimm. pi Sael. e Cham. Nolt 



NoviL FL Holsat, p. 19. Chamiss. in Linnaa, 2, p. 182. t. 



»./ 10. 

 Hab. Ponds and slow streams, common in New England, and 



westward. In the western part of New York it attains to a much 

 larger size than with us, and often not a little resembles Schol- 

 lera, with which I found it growing. Stem much compressed, 

 and winged, very much and long branched, l-2£ feet long. 

 Leaves dark green, all submersed and membranaceous, linear, 

 above sensibly a little attenuate toward the abruptly and shortly 

 acuminate and cuspidate tip, at the base not attenuate, sessile; 

 3-5-nerved * sparsely and obsoletely here and there veined ; 3£ 

 to 8 inches long by 1J to 2 lines wide ; the lowest ones shorter, 

 broad-linear, obtusish and submucronate, many-nerved. Stipules 

 large, delicate, pellucid, green with whitish margins, finely many- 

 nerved and the two lateral nerves prominent, acuminate and at 

 length lacerate. Peduncles compressed, not reflexed in fruit, com- 



Second Series, Vol VII, No. 21.— May, 1849. 45 



