CLASS I. ORDER II. 3 



This plant is less than half the height of the preceding, but 

 thicker in all its parts, and always distinguishable at sight. 

 Spikes very thick, with remarkably acute scales. It is wholly 

 unlike S. ambigua Mx., of which I have southern specimens 

 with slender branches and spikes and obtuse scales. 



Different species of Salicornia are among the maritime plants 

 employed in the manufacture of soda. They are used at table - 

 as pickles. 



2. HIPPURIS. 

 HiPPURis VULGARIS. L. Mares tail. 



Leaves in whorls of eight, linear-lanceolate, acute. 



An aquatic plant, partly floating, partly emerged; the emerg- 

 ed leaves smallest. Flowers axillary ; calyx minute, with a 

 lateral stamen, the style passing through the anther. I have 

 specimens from Vermont and Canada. — June. — Perennial. 



DIGYNIA. 



3. PODOSTEMUM. 



PoDOSTEMUM CERATOPHYLLUM. Mx. Thread foot. 



Leaves bristly, many-r^rterl; 



An obscure, tough plant, with setaceous leaves, growing under 

 water, with the roots attached to stones at the bottom. Flowers 

 solitary, pedicelled, monoecious. — Amherst. — Hitchcock. 



4. CALLITRICHE. 



Callitriche aquatica. Sm. Water starwort. 



Stem floating ; npper leaves spatulate, obovate. 

 Synonym. Callitriche verna. L. 



The stem is filiform, floating, and composed of a double tube. 

 The leaves are small, opposite, inversely ovate or wedge-shaped, 

 rounded at the end, (not acute as in the European;) the upper 

 ones forming star-like tufts on the ends of the stem. Flowers 

 minute, axillary, solitary, sessile. It grows in fresh water, sup- 

 ported by its floating upper leaves ; flowering above, but ripen- 

 ing its seeds under water. — Found in Roxbury. — Annual. 



