398 



CALL1TRICIIACE.*:. (\YATER-STARWORT FAMILY.) 



1. SAURURUS, L Lizard's-Tail. 



Stamens 1-8, with long club-shaped filaments. Fruit somewhat fleshy, com- 

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

 — Flowers white. 



1. S. cernuus, 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 hanks, 

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

 Spikes 4' -6' long. 



Order 116. CERATOPHYLLACE^E. (IIorxwort 



Family.) 



Submerged aquatic herbs, with filiform jointed and branching stems, 

 finely dissected whorled 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 orthotropaus ovule. Achenium 

 compressed, pointed witli the slender persistent style. Albumen none. 

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



1. CERATOPHYLLUM, L. Hornwort. 



1. C. demersum, L. Leaves rigid, G - 9 in a whorl, once or twice forking, 

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

 on the sides, and armed near the base, with 2 lateral widely-spreading slender 

 spines. — 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 segments bristly-toothed; ovaries warty, unarmed; ache- 

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

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

 and, West Florida. .May.— Stems 6'- 12' long. 



3. C. Sllbmersum, L. Leaves hair-like, 3-4 times forking. bri>tlv- 

 tootbed ; achenium oblong, slightly compressed, tubercular-roughened, with 

 rounded mar-ins, unarmed. — South Florida, Dr. Bluihjdt. — Stems 6' -12' 

 lomr. 



Ordeb 117. ( AT.T.ITRICHACE^E. (Wa-^er-Starwort 



F \MILY.) 



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

 polygamous flowers without floral envelopes. Stamen mostly solitary, fc- 

 bracted in the sterile flower. Filament slender: anther reniform, the 



