224 PLANTS OF MASSACHUSETTS. 



near the 5 sessile stigmas ; berry 1 -celled, many-seeded, situated 

 on the filiform branches or leaves. 



C. vulgaris. L. Feather-beds. A slender, flexile plant with 

 a small stem, surrounded at short distances by a whorl of about 

 8 slender, filiform leaves. As it grows immersed in dense ex- 

 tensive tufts, it looks like a soft bed of feather-like materials, and 

 in running water is a beautifully waving plant. Taken from the 

 water, it becomes very brittle, and has a very putrid odor. 



C. flexilis. L. Much resembles the other, is nearly as slen- 

 der, but a stiffer plant. In stagnant water with Najas ; Stock- 

 bridge. 



Ruppia. L. 4. 4. 



R. maritima. L. Sea Teasel-Grass. Two flowers on a 

 spadix, rising from the leaves ; perianth none ; stamens 4-sessile, 

 and 4 drupes. 



In salt marshes near Boston ; a grass-like plant with immersed, 

 linear leaves ; sends its spike-form flower-stem out of the water 

 to present the flowers to the sun ; stem is somewhat spiral, so as 

 to unwind as the water rises, and keep the flower in the air. 

 Named after a German botanist, Ruppi. 



Potamogeton. L. 4. 4. Pond-weed. 

 From the Greek for near and river ; aquatics, common in Eu- 

 rope and North America ; perianth 4-leafed, no corolla, style 

 wanting, 4 seeds. Nine species are found in our waters. Flower 

 inconspicuous, projecting from the water by its long and porous 

 leaves. Some have floating as well as immersed leaves, and some 

 only the latter ; the stem bearing flowers projecting from the 

 water. Some are coarse plants, some much more delicate. 

 After the time of flowering, the stem is chiefly under water. In 

 some species the leaves are long and narrow, and are beautiful as 

 they wave in running streams. 



P. compressum. W. Compressed stem, with linear, obtuse 

 leaves. 



