MONOECIA.— TRIANDRU. 33' 



TRIANDRIA. 



.29. TYFHA. Reed-mace. Avoided 



1. T. laiifolia : leaves linear ; sterile and fertile spikes 



approximate on the same rachis, both cylindrical. 

 IIAB. Water. June— July. U . Culm 5 ft . high ; 

 spikes dense; leav. 1 in. broad, 



2. T . angustifolia : leaves linear, canaliculate, semi- 



cylindric below and flattish above ; sterile and fer- 

 tile spikes a little separate. 



HAB. Water, June— July. U- Culm 4— 5 ft. 

 high; leav. 5-6 lin. broad. 



530. SPARGANIUM. Burr-reed. Aroidea;. 



1. S. ramosum : leaves triangular at the base, their 



sides concave ; common flower stalk branched ; 

 stigma linear. 

 HAB. Borders of lakes, &c. Aug.— -Sept. U. 

 Two ft. high; leav. ensif, long. 



2. S. americanum : lower leaves equal with, or ex- 



ceeding the stem, which is nearly simple ; floral 

 ones concave at the base and erect ; stigma sim- 

 ple, ovate-oblong, oblique, scarcely more than 

 half the length of the style. 

 IIAB. Lakes. Aug. H. Stem 12 in. high ; lower 

 leav. curinate ; fertile heads 2 — 5. 



3. S. nutans : leaves long, flat, floating ; common 



flower-stalk simple ; stigma ovate, very short ; 

 head of sterile flowers subsolitary. 

 IIAB. Lakes. Aug. U. Stem long, slend.; leav. 

 very narrow, linear, thin. 



531. CAREX.« Sedge. Cyperoideat. 



A. Inflorescence dioecious. 



1. C. sterilis : spikes dioecious ; sterile 3—5; fertile 

 about 6, (sometimes androgynous ;) fruit ovate, 



a Tor full descriptions of the species enumerated below, sec 

 ihe Monograph of North American Carices, by Rev. Mr. Sclnvci 

 nitz and myself, in the Annals of the Lyceum of Nat. History. 



