79 



by European authorities, our plant is not the same, and it only 

 creates confusion to employ the name. 



Pennsylvania, White Mountain ponds and northward. 

 4- .S, simplex, Huds. (Fl. Ang., Ed. 2, p". 401.) 



Leaves more or less triquetrous, 5-8 mm wide; stems slender, 

 erect, 1^-6 dm, high; inflorescence 5-20 cm. in length; stam- 

 inate heads 4-6, pistillate 2-4, sessile or the lowest peduncled, 

 supra-axillary or axillary (v iV^^/to////, Engelm.); ripe fruiting 

 heads 12-15 mm. in diameter; nutlets fusiform or narrowly ob- 

 long, obtusely angled at the apex, the body about 4 mm. long, 

 more or less contracted in the middle; stigmas hnear, equal to 

 or shorter than the styles; stipe about 2 mm. long. 



This is often found In a dwarf state with a stem only 10 or 12 

 cm. high, leaves short and 2 or 3 mm. wide, and the inflorescence 

 2 or 3 cm. in lenorth. 



Canada to the Middle States, California and northward to 

 British Columbia. (Eu.) 



•^Var. MULTIPEDUNCULATA, n. vaf, 



A form sent from Great Falls, Montana^ by Mr. R. S. 

 Williams, which has tlie heads aggregated, most of them on 

 simple or branching peduncles ; nutlets very slender and long- 

 beaked ; scales long, slender and toothed ; and not infrequently 

 double stigmas. 



Var. angiistifolmm, (Michx.), Engelm., in Gray, Manual, Ed. 

 5* p. 481. {S, angiistifolium,W\c\\yi., Flor. Bon Am., ii., p. 189;* 

 ^- affine^ Schnizl. Nat. Pfl. Typh., 1845, p. 27.) 



Floating in deep water; stems slender; leaves long and nar- 

 row, 1-5 mm. wide, flat, with sheaths often inflated at the base; 

 inflorescence 3- 10 cm. long; staminate heads 1-4, pistillate 1-4, 

 sessile, supra-axillary or the lower on supra-axillary pedunchs, 

 the lowest often remote as a peduncle 4-7 cm. in length ; ripe 

 fruiting heads 7-15 mm. in diam.; nutlets often contracted in the 

 middle; stigmas linear or oval, equal to or shorter than the style. 

 In European specimens of this which I have examined the in- 

 florescence is sometimes as much as 20 cm. long, the lowest fertile 



*r)r. Engelmann writes in a manuscript note in my possession that he, himself, 

 has seen Michaux's specimen at Paris. To this name, therefore, belongs the right of 

 priority. 



