THE Fl.oi; \ < 'I NEBRA8K \. 



Draparnaiidia plumosa (Vai oh.) a a. Syst. 58. L824. 



Batrachospermum /»/»m<< urn Vai ch. Hist. Conf. t. XI . f. 2. I 



Pale or yellowish green, 1 •"> cm. long; main filament hyaline, oftei 



broad, cells l , tol 1 , times Longer than broad, verj slightly or doI at all 

 constricted at the joints; Lower cells of the branches 1" 12 broad equal 

 to double the diameter; upper cells cylindrical, G '.' broad, 2 3 times the 

 diameter iu length, sometimes not piliferous. 



Closely related to the next, but distinguished bj the absence "i any constric 

 tion in the colls of the main filament. 



Iu creeks, etc., Lincoln. PL, XIX., Fig. 1 



Draparnamlia glome rat a (Vauch.) a .. I c. 59. 

 Batrachospermum glomeratum Vauch. 1. c. p. 11 1 



Pale green, 1-10 cm. long, often swimming; main filament almost colorless, 

 30-70 ii broad; lower cells equal to or somewhat shorter than the diameter, 

 constricted at the joints, upper cells longer, mostly hyaline, wit h a narrow, 

 light green, transverse chlorophyll-band, always sterile; primary branches 

 spreading at right angles, fascicles of branches obtuse, oval, crowded, al- 

 ternate or opposite. 

 Streams, etc., Lincoln, Minden, Wahoo. PI. XIX.. Fig. J. 



Family.— CLA.DOPHORACEAE. 



Thallus aquatic, filiform, articulate, either simple or sub-simple; repeatedly branched 

 or with short rhizoid branches; free-swimming or attached by hyaline rhizoids; vegetative 

 cells multinucleate; chloroplasts parietal, laminiform, fragmentary, or disciform, ro- 

 tund to angular, sub-seriate; cell-membrane firm, not rarely Lamellose. 



Propagation by 2-4-ciliate zoogonidia, which are developed in Large numbers in cells, 

 escaping through a pore in the cell-wall. 



1. CLADOPHORA Ktjetz. Linnaea XVII., 9L L843. 



Thallus free, or adnate, growing in water, or in dam] positions; filaments 

 articulate, branching; vegetative cells sub-cylindrical, plurinucleate; 

 chloroplasts disciform, parietal; propagation by small, 2 ciliate 

 nidia, and by larger 4-ciliate zoogonidia arising from simultaneous divi 

 sion of the plasm; reproduction by copulation of zoogonidia 



Etymology: Greek kKoSoq, branch, and . bear. 



Cladophora fracta (Dillw.) Kuetz. Phyc. gener. 26a 184a 

 Conferva fracta Dillwyx Brit. Conf. 65. XIV. L809. 



Branches few, divaricate, often secund; cell contents not Bpirally disposed, 

 dark green, very granular; cell membrane sometimes very thick; art ica 

 lations more or less swollen; fertile cells never terminal, basal, or Inter 

 calated; diameter of stem, 50 L20 ; cells, 1 I times Longer; diameter ol 

 branches, 15 LO «; cells, 3 6 times Longer. 



Var.— gossypina Kuetz. Filaments ion- and slender, sparsely branched; artlca 

 lations 6 LO times longer than broad, often of a Bilkj appearance, loosely 



interwoven into Large masses. 

 Both type and variety are common in springs and ponds, probably through- 

 out the state. 



