530 CYrKUACK-i:. (skdck i amu.v.) 



orliic'ular, stronf;l_v writikli'd ; tiibcrtlf (Muniircssi'd, vny sliort, sessile, but not 

 lUiunriit on tlio I'dgi's of the nut. (Stir|)iis niteiis, Vditi ) — Shiillow ])iiK'- 

 l)iinvn ponds, Florida to Nortli Carolimi. July. (J) — Culms conuuoMly root- 

 ing at the lower joints. 



1'. sriiJfoiuKS, Torr., if within our limits, may be known hy its ncurly smooth 

 nut, and slender beak-like decurrent tubercle. 



18. DICHROMENA, IJicbanl. 



Spikes compressed, few-flowered, aggregated in a teniiinal head, and sur- 

 rounded l)y an involucre of several leaves, which are commonly white at the 

 base. Scales imbricated in few rows, most of them bearing abortive flowers. 

 Stamens 3. Style 2-clcft. Nut lenticular, crowned with the broad and persist- 

 ent base of the style. Perianth none. Perennials. Culms jointless, leafy at 

 the base. Scales white, membranaceous. 



1. D. leucoeephala, Michx. Culms (1°-1^° high) slender, 3-anglcd ; 

 leaves narrowly linear ; involucre of 4 - 7 narrow leaves ; nut orbicular, wrinkled ; 

 tubercle flat, iiroadly conical, sessile, but not decurrent. — Damp soil, Florida to 

 North Carolina. Aug. and Sept. — Involucre unchanged in drying. 



2. D. latifolia, Baldw. Culms stout (2° -3° high), nearly terete ; leaves 

 broadly linear, elongated; leaves of the involucre 8-9, tapering from the broad 

 (3"_4" wide) base to the slender summit, becoming reddish ; nut round-obovate, 

 faintly wrinkled ; tubercle flat, conical, obtuse, the sides decurrent on the edges 

 of the nut. — Low pine barrens, Florida to North Carolina. May -July. — 

 Heads larger than those of the preceding. 



19. CLADIUM, Browne. 



Spikes ovate, 1 - 2-flowered. Scales loosely imbricated, the lower ones empty. 

 Perianth none. Stamens 2. Style 2-3-cleft, the divisions often 2- 3-cleft, de- 

 ciduous. Nut globo.sc-ovatc, the pericarp thickened and corky near the apex. 

 Tubercle none. — Culms tall. Spikes disposed in axillary and terminal cyme- 

 like panicles. 



1. C. effusum, Torr. (Sa\v-Gk.\s.s.) Culms (4° - 8° high) nearly terete; 

 leaves linear, elongated, saw-edged ; panicles numerous, diffuse ; spikes small, 

 3-4 in a cluster, deep brown ; scales about 6, the uppermost bearing a perfect 

 flower, the next below staminiferous, the others empty ; nut ovate, pointed, 

 wrinkled. (Schfcnus cffusus, Siraiis.) — Fresh or brackish marshes along the 

 coast, Florida to North Carolina, and westward. July and Aug. 



20. SCLERIA, L. Nut Rush. 



Flowers moncccious. Sterile spike few - many-flowered. Scales loosely im- 

 bricated in 2 - 3 rows. Fertile flowers solitary, separate or at the base of the 

 sterile spike. Stamens 1-3. Style 3-clefi:. Nut globose or ovate, stony or 

 bony. — Chiefly perennials, with creeping rootstocks, and triangular leafy culms. 

 Spikes clustered, lateral and terminal. 



