several in a series on very short pedicels, mostly sessile, ovoid to 

 subglobose, opening by an oblique pore in a narrow beak which 

 faces in an opposite direction from the neighboring oogonium, 

 100-125/x in diameter, 180-250/x long; antheridia subcyhndric, strong- 

 ly recurved, one on each side of a pair or series of oogonia; oospores 

 globose, with a 3-layered membrane, 80-120/x in diameter, not filling 

 the oogonium. 



Forming a soft, felt-like mat in spring seeps and on moist shady 

 banks of streams, etc. Wis. 



Vaucheria geminata (Vauch.) De Candolle 1805, p. 62 



PL 68, Figs. 2, 3 



Aquatic or on very moist soil; filaments coarse and freely branched, 

 80-100/x in diameter; oogonia in pairs, ovate to subglobose, borne 

 laterally near the end of a short stipitate branch of the main axis, 

 with 1 antheridium circinate or strongly reflected; oogonia with 

 pores directed vertically, 60-80/x in diameter, 70-90(U, long; oospores 

 with thick, 3-layered membranes, completely filling and the same 

 shape as the oogonia. 



Forming floating, tangled mats in marshes and cut-oi > from lakes 

 protected from wave action; in ditches of shallow water Mich., Wis. 



Vaucheria geminata var. depressa Transeau 1917, . 228 

 A variety differing from the typical by having the pedicels of 

 the oogonia longer than in the typical, arising from a snort lateral 

 branch and curved so that the oogonia are in contact with the 

 main filament. 

 Mich. 



Vaucheria hamata (Vauch.) De Candolle 1805, p. 63 

 Filaments rather slender; monoecious; oogonia solitary, or rarely 

 2 together, ovate to somewhat lunate, with the inner or lower margin 

 somewhat concave, borne on a pedicel at the end of a lateral branch 

 from the main axis, 60-75/x in diameter, 75-90/x long; antheridium 

 tubular, circinate, arising from near the base of the oogonium 

 pedicel; oospore with a 4-layered membrane, completely filling the 

 oogonium, containing a dark granular spot. 



Floating, tangled mats in quiet water. Mich., Wis. 



Vaucheria longipes Collins 1907, p. 201 

 PI. 67, Fig. 5 

 Filaments rather coarse, 80-90/x in diameter; monoecious; sex 

 organs on a long ( 1-4 mm. ) lateral branch, 30-40/a in diameter; the 



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