Chara. CLXVI. CHARACEiE. 637 



A. Carouniana. Willd. 



Leaves arranged in two rows upon the rhizoma, imbricated, oblong-subu- 

 late, obtusish, spreading, fleshy, the floating ones reddish beneath. — ® A small 

 plant, resembling some of the mosses, floating in still or sluggish waters. North- 

 ern and Western States. It has been found in Lake Ontario, and in Cayuga 

 Marsh {Eaton), also in the Ohio river at Louisville, Ky. {M'Murt,) and other 

 western rivers. 



Order CLXVI. CHAKACE^.— Charads. 



PtenZ aquatic, suhmersed; axis consisting of parallel, tubular cells, either transparent, or encrusted 

 with carbonate of lime, furnished with_ leaves or Dranches consisting of verticillate tubes. 



Organs of reproduction consisting of round, succulent globules, containing lilaraents and a fluid ; and 

 axillary nucules formed of a tew short tubes twisted spirally around a centre, endowed with the power 

 ol germination. 



These are remarkable for the distinct current, readily observable with a microscope, in the fluid of each 

 tube of which the plant is composed. The currents instantly cease when the plant is injured. 



CHARA. 



Gr. T^atpb), to rejoice; because it delights in the water? 



Grlobules minute, round, reddish, dehiscent, filled with a mass of 

 elastic filaments; nucules (thecas?) sessile, oval, solitary, membrana- 

 ceous, spirally striated, the summit indistinctly cleft into 5 valves, 

 the interior filled with minute spores. 



1. C. vulgaris. Feather-beds. 



Sts. and branches naked at base ; branches terete, leafy at the joints ; Ivs. (or 

 brancUets 7) oblong-subulate ; bracts shorter than the fruit. — A slender, flexile 

 plant of a dull green color, found in ponds and ditches generally stagnant. It 

 appears in dense tufts, like a soft bed, undulating with the motion of the water. 

 When taken out, it has an offensive odor. Stems slender, a foot or more long, 

 with a verticil of about 8 filiform branchlets at each joint. June. 



2. C. FLEXILIS. 



St. translucent, naked; branches jointless, leafless, compressed; nucules 



lateral, naked. — Found in ponds, Stockbridge, Ms., in company with Najas. 



Resembles the last, but the stems are shorter and more erect, nearly destitute of 



the verticils of branchlets. It is annual, as are also all the other species. Aug. 



3. C. foliosa. Willd. (C. squamosa. Desf.) 



St. solitary, 8 — 10' high, calcarious and brittle, scabrous, striate, with 2 

 or 3 branches, the younger parts bearing numerous whorls of minute, leaf- 

 like scales ; branchlets about 13 in a whorl, 6 — 9" long, involucrate at their ori- 

 gin by a dense whorl of subulate scales ; each branchlet with 4 — 7 whorls of 

 nearly obsolete scales; theca 2 — 4, on the inner side and lower half of each 

 branchlet. — (I) Rivers, Ohio, Riddell, Ind. ! Aug. 



4. C. HUMiLis. Riddell. 



St. incrusted, solitary and branching, scabrous, not sulcate, 2 — 3' high ; 

 branchlets 8 — 10 in a whorl, without an involucre, generally equaling the inter- 

 nodes (6 — 9") ; theccE 1 — 2 on each of the branchlets in the upper whorls. — 

 In shallow water, rivers, Ohio, Riddell. Color deep green. Resembles the 

 last. Aug. 



5. C. SABULosA. Riddell. Slone-ioort. 



St. 18' high, thickly encrusted and very brittle, with a few erect branches, 

 subsulcate, papillose ; branchlets generally 10, sometimes 8, in each whorl, with- 

 out an involucre, nearly 6" long, (about half as long as the internodes,) each 

 with 2 — i verticils of scales; thcca: on the inner side of the branchlets, in the 

 axils of the scales. — (J) Pools of clear water, 2 or 3 feet deep, Ohio, Ind. ! Color 

 light pea-green. Aug. 

 /?. spiralis. Riddell. Stems spirally sulcate ; branchlets longer. 



