CYPEKACEAE. 



49 



1. Fimbristylis castlbnea 



(Michx.) Vahl. Marsh Fimbri- 

 STYLis. (Fig. 73.) Perennial by 

 a thick base; culms slender, 3- 

 angled, 2^° high or less, usually 

 exceeding the leaves. Leaves in- 

 volute, less than 1" wide; leaves of 

 the involucre 2-4, short; umbel 

 simple or compound, the rays ^'-2' 

 long; central spikelets sessile; 

 spikelets oblong, 3"-6" long, 

 about I5" in diameter; scales thin, 

 brown with a lighter midvein, 

 broadly oblong or nearly orbicular, 

 obtuse or mucronate ; stamens 2-3 ; 

 style 2-cleft; achene obovate or ob- 

 long, biconvex, pale brown. [Scir- 

 pus castaneus Michx.; Fimhristylis 

 spadicea of Moore, and referred to 

 that species by C. B. Clarke.] 



Frequent in marshes. Native. 

 Eastern United States, Bahamas and 

 Cuba. Summer and autumn. 



6. DICHROMENA Michx. 



Leafy-stemmed sedges, peren- 

 nial by rootstocks, the spikelets in 

 a terminal head involucrate by the upper leaves. Spikelets compressed, several- 

 many-flowered. Scales spirally imbricated, several with imperfect flowers, or 

 empty. Perianth none. Stamens 3. Style 2-cleft. Achene lenticular, trans- 

 versely rugose, crowned with the broad base of the style (tubercle). [Greek, 

 alluding to the two-colored Involucral leaves.] About 20 species, of America, 

 the following typical. 



1. Dichromena colord,ta 



(L.) A. S. Hitchcock. White- 

 headed Rush. Narrow-leaved 

 Dichromena. (Fig. 74.) Gla- 

 brous; culm slender, erect, rather 

 sharply triangular, l°-2^° tall. 

 Leaves distant, narrowly linear, 

 about 1'" wide, much shorter 

 than the culm, those of the in- 

 volucre 4-6, reflexed when ma- 

 ture, yellowish white at the base; 

 head globose, o"-10" in diam- 

 eter; spikelets narrowly oblong, 

 acute; scales membranous, lan- 

 ceolate, nearly white, l-ne'-vod, 

 subacute at the apex; achene ob- 

 ovate, brown, nearly truncate at 

 the summit, compressed, covered 

 by the tubercle. [Schoe7iu3 

 coloratiis L. ; D. leucocephahi 

 Michx.; Hhynchospora stellata 

 of Rein, Reade, H. B. Small and 

 Lefroy; i?. pitra of Rein, Lefroy 

 and Ilemsley.] 



