8 



NITELLA GLOMERULIFERA, A. Br. Sillim. Am. Journ., 1843, p. 

 92, name only. 



Plants 10 to 15 cm., high, growing in clusters at the bottom 

 of clear, still lakes, often at a considerable depth, easily recog- 

 nized by the dense masses of fruiting verticils which are col- 

 lected in glomeruli, attaining a diameter of 8 or 10 mm., and are 

 subtended by simple or once-branched sterile leaves ; which 

 long overtop the glomeruli ; sterile leaves often 40 to 40 mm. in 

 length ; once-divided ; terminals 2-4, one-third to one-half the 

 whole length of the leaf ; gradually tapering to a sharp point. 



Fertile verticiles arise, usually, in the " axils " of the sterile 

 leaves, generally numerous and becoming repeatedly branched 

 and abbreviated form dense masses; glomeruli often 10 mm. in 

 diameter. Leaves of the fertile verticils 8 in number, about 

 2 mm. long, of which about half is taken by the terminals, 2 to 

 4, rarely 5, in number. Antheridia about 400 // in diam. ; coron- 

 ulae persistent ; oospore 400 /< long, -500 /< broad with seven 

 ridges, not prominent ; membrane of the oospore thickly 

 studded with roundish elevations or granules ; these granules 

 average 1.5 // in diam. (5 granules with their spaces in 15 (JL). 

 The markings on the oospore clearly separate this species 

 from all the others of this section, though the plant is clearly 

 and strikingly distinct in other ways. 



The first specimens appear to have been collected in the Mer- 

 rimac River, Mass., by Green. Since then in Massachusetts, 

 several places, Farlow, etc., New York, Lake Champlain, 

 Morong ; Lake Ontario, Allen ; New Jersey, Allen ; Chatauqua 

 Lake, Allen ; Ohio, Peck; Louisiana, in March, 1836, Dr. Carpen- 

 ter, etc., etc. Its range thus seems large, but it appears to be 

 a more northern than southern species (the reverse of subglom- 

 erata). 



Explanation of Plate : i x 25, a fruiting plant "glomeruli " 



not large nor dense, rather immature ; 2 x 25, a portion of a 



glomerulus, showing only a single stem of a fruiting verticil, 



and at " bb " the remains of sterile leaves ; 3, a mature oospore 



x 50 ; 4, a bit of the membrane of the oospore highly magnified. 



