Stigeocloniutn nanum Kuetzing 1849, p. 354 

 PL 9, Figs. 7, 8 



Thallus composed of short-tufted filaments, the branches arising 

 alternately and tapering to blunt points. Cells of the branches scarce- 

 ly smaller than those of the main axis, 6-8/a in diameter, 10-18/i, long. 

 Prostrate portion of the plant expansive, pseudoparenchymatous, 

 becoming filamentous; the cells subglobose and giving rise to ver- 

 tical branches. 



This species forms green, fuzzy films on submerged aquatics, es- 

 pecially on the cukns of rushes, and on wood. As pointed out by 

 Collins (1909, p. 300), the morphology of this plant suggests that 

 it is a juvenile or growth form of another species. 



Attached to wood in flowing water. Mich., Wis. 



Stigeoclonium pachydermum Prescott 1944, p. 350 

 PI. 12, Figs. 1-4, 9, 10 



Filaments much-branched, erect, with numerous basal, downward- 

 projecting rhizoidal branches; branches in the upper portion irregu- 

 larly disposed and extremely varied in form, mostly alternate, but 

 with one branch arising immediately above another on the opposite 

 side of the filament, or in a plane at right angles to it; branches often 

 developing from short, barrel-shaped cells; many thorn-like and 

 irregular, downward-projecting branches developing from the upper 

 part of the main axis; branches tapering to a blunt point and 

 frequently ending in somewhat enlarged quadrangular-globose 

 sporangial cells, which may be intercalary near the ends of short 

 branches also. Cells in the main axis 19.5-21/a in diameter, in the 

 branches 15-16/* in diameter; cylindrical and several times longer 

 than wide, short and barrel-shaped in the same filament. Walls of 

 the cells in the main axis 3-4/x, thick. 



The chief characteristics of this species are the irregularly arranged 

 crooked branches and the thick walls. In its coarse habit the plant 

 resembles S. luhricmn, which is, however, a species with opposite 

 branching. 



This plant has been found but once in the Creat Lakes region, 

 growing in the shallow water of High Lake, Vilas County, Wisconsin. 



Stigeoclonium polymorphum (Franke) Heering 1914, p. 87 



PI. 9, Fig. 9 

 Filaments epiphytic or endophytic, short, and sparsely branched; 

 arising from an extensive prostrate, pseudoparenchymatous, or mon- 

 ostromatic and radiating portion. Upright branches ending in long 



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