308 CALLITUICIIACF./E. (WATKIJ-STARWOUT FAMILY.) 



1. SAUEURUS, L Lizard's-Tail. 



Stamens 4-8, with long club-shaped filaments. Fruit somewhat fleshy, com- 

 posed of 3 - 4 partly united 1 - 2-seeded carpels, pointed with ad many stigmas. 

 — Flowers white. 



1. S. cemuus, L Stem erect, branching; leaves petiolcd, cordate-ovate, 

 or oblong-ovate, acuminate ; spikes white, terminal, nodding at the apex; flow- 

 ers numerous, each from the axil of a small bract. — Marshes and muddy banks, 

 Florida, and northward. May -Aug. — lihizoma creeping. Stem l°-2° high. 

 Spikes 4'- C long. 



Order 116. CERATOPHYLLACE^. (Horn wort 

 Family.) 



Submerged aquatic berbs, with filiform jointed and branching stems, 

 finely dissected whirled leaves, and small axillary monoecious flowers, 

 destitute of floral envelopes, but surrounded by an involucre of 8-12 

 linear leaves. Anthers 12 — 24, oblong, 2 — 3-toothed, sessile. Ovary 

 solitary, simple, with a single suspended orthotropous ovule. Achenium 

 compressed, pointed with the Blender persistent style. Albumen none. 

 Cotyledons 4. Plumule conspicuous. — Consisting of the single genus 



1. CERATOPHYLLUM, L. Hosnwom. 



1. C. demertjum, L. Leaves rigid, 6-9 in awhorl, once or twice forking, 

 with the lobes Bpiny-toothed ; achenium oval, compressed, tubercular-roughened 



on the side-, and armed near the base with 2 lateral widely-Spreading slender 

 Bpines. — In Stillwater, Florida, and northward. Sept. and Oct. — Stems 1°- 

 4° long. Leaves near the end of the branches much crowded. 



2. C. echinatum, Gray? Leaves weak, 9-12 in a whorl, 3-4 times 

 forking, the ultimate Begments bristly-toothed; ovaries warty, unarmed; aehe- 

 iiium oblong, tubercular-roughened on the sides, the edges margined and armed 

 with 5-7 strong and spreading spines. — Shallow ponds, on St. Vincent's Isl- 

 and, West Florida, May.— Stems <;'-i2' long. 



3. C. SUbmerSUm, L. Leaves hair-like, 3-4 times forking, hri-tly- 



i ; achenium oblong, Blightly compressed, tubercular-roughened, with 

 rounded margins, unarmed. — South Florida, Dr. Blodgett. — Stems C-12' 



Order 117. r W.LITRK II \ri: K. (Water-Starwort 



Fame j .) 



Small aquatic annuals, with opposite entire leaves, and solitary axillary 

 polygamous flowers without floral envelopes. Stamen mostly solitary, 2« 

 brae ted in the sterile flower. Filament .slender: anther renifbrm, the 



