POTAMOGETON. NAJADACE^. 257 



Crooked lake {Dr. Sartwell). Fl. August. I have not seen the ripe fruit of this plant, but 

 there can be little doubt of its being the P. pusillus of Chamisso and Schlechtendal, the var. 

 A. (/. c.) agreeing very minutely with our specimens. 



8. PoTAMOGETON PAUCiFLORUS, PuTsh. Few-Jlowerecl Pondweed, 



Stem slender, mucli branched, compressed ; leaves very narrow and linear, acute, membra- 

 naceous, 3-nerved without connecting veins ; spikes capitate, few- (4 - 6-) flowered ; fruit 

 obovoid, convex on the side, apiculate at the summit, cristate on the back. ^ Purs/i, ^. 1. 

 p. 121 ; Torr.fl. \.p.98; Bigel. fl. Bost. p. 64 ; Cham. <^- Schlecht. I. c. p. 176. t. 4./. 7; 

 Beck, hot. p. 386; Darlingt. fl. Cest. p. 116; Kunth, enum. 3. p. 136. P. gramineum, 

 Michx.fl. 1. p. 102. 



A very slender species, wholly submersed ; the stem almost filiform. Leaves 1-2 inches 

 long, and rarely more than a line wide ; the lateral nerves indistinct. Stipules membranaceous, 

 obtuse or mucronulate, linear-oblong, furnished with a very minute gland on each side at the 

 base. Spikes very short, seldom more than 6-flowered, on a clavate peduncle about half an 

 inch long. Fruit rather large for the size of the plant, somewhat acuminate, distinctly crested 

 on the back ; the shell thick and hard. 



Ponds, lakes and slow streams. August. Distinguished from the preceding by its smaller 

 stems, narrower leaves, short capitate few-flowered spikes, and crested fruit. 



^ 2. Stipules adnate to the base of the leaves, which are all submerged and similar in farm. 



9. PoTAMOGETON PECTiNATUs, Linn. Fcnnel-leavcd PoTidweed. 



Leaves setaceous-filiform, channelled, with a longitudinal cavity each side of the midrib ; 

 spikes on long peduncles, interrupted. — Linn. sp. 1. p. 127; Pursh fl. 1. p. 121 ; Torr. 

 fl. 1. p. 198; Cham. <^ Schlecht. I. c. p. 164. t. 4. /. 2; Beck, hot. p. 336 ; Kunth, enum. 

 3. p. 137. P. marinum, Linn. I. c. ; Miclix.fl. 1. p. 102. P. exstipulalum, Muhl. cat. p. 17. 



Stem filiform, much branched, dichotomous. Leaves distichous, very numerous, very 

 slender, with a tube-like cavity running ihe whole length on each side of the midrib, attenuated 

 to a fine point. Stipules membranaceous, adnate to the base of the leaf, and forming a 

 sheath. Peduncles mostly elongated. Spike three-fourths of an inch to an inch long, with 

 distinct intervals (which are sometimes considerable) between the clusters of flowers. 



Saltwater ditches and shallow bays, near New-York, and on Long Island. Also in fresh 

 water, near Watertown {Dr. day). Fl. August. Fr. October. 

 [Flora — Vol 2.] 33 



