358 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



652. Hypmim symiuetrieiim R. & C— Sub-species of H. uncinatum r 

 leaves moderately striate, capsule narrow, cylindric, always exactly erect, 

 symmetric; seta sometimes in pairs. Ren. ibid. 379. — Rocky Mountain 

 and Pacific Coast region. 



553. H)pnum fluitans Je.tnbernati Ren. — Monoicous: tufts pale green, 

 sometimes rather dense, 6-10 cm. high: leaves feebly homotropous except 

 at summit, oblong or oV)long-lanceolate, narrowed into an often short and 

 rather broad acumen, truncate at base, sinuolate or slightly denticulate, 

 sometimes dentate; costa slender (47/<), little surpassing the middle; median 

 cells very long, alar little dilated, not vesicular, poorly delimited: seta 4-6 

 cm.— Ren. ibid. 381. 



564. Hypnum fluitans Delamarei R. & C— Monoicous: plants tall, 

 slender (25 cm.): tufts floating, pale green at surface, dark brown within; 

 some stems regularly pinnate: stem leaves falciform, strikingly recurved on 

 some branches, on others simply secund, narrowly lanceolate, slenderly 

 acuminate or short subulate, plainly dentate at summit; branch leaves 

 linear, spreading, flexuous; costa colored, narrow (40-60//), little surpassing 

 the middle: median cells very long and narrow, remainder elongated and 

 compact to the base, basal with walls a little thickened, alar small, occu- 

 pying almost all the base, not forming distinct auricles: capsule short, 

 erect, blackish; seta 4-5 cm., surpassing the stem. Ren. ibid. 384. 

 Miquelon Is. 



5.i5. Hypjiusn fluitans piiinatum Boul.— Tufts yellowish green: stem 

 rather short (8-10 cm.), erect, stout, usually pinnate: leaves falciform, oval 

 or oval-oblong or narrower at base, slenderly acuminate or short subulate, 

 usually denticulate at base and apex; costa reaching middle of point; auri- 

 cles large, swollen, rounded composed of rather numerous cells with gen- 

 erally unthickened walls. Ren. I c. — Miquelon Is. 



556. Hypnum fluitans falcifolium Ren.— Usually purplish or mixed 

 with green or brown: stem 5-10 cm or longer, pinnate: leaves falciform, 

 rather distant, lanceolate narrowed into a long subula often spirally 

 twisted and sparingly toothed costa broad (80-90w) at base, ending in the 

 subula or reaching the point but not distinctly excurrent; median cells 

 long and narrow; auricles composed of cells usually thickened and colored. 

 Renauld, ibid. 387 . — Yellowstone Park. 



657. Hypnum fluitaus hemiueuron R. & C— Tufts pale green, de- 

 pessed, intricate, small: stem prostrate, ascending at tip, slender, very 

 short (1-3 cm.), vaguely branched, radicles distinct: leaves slightly homo- 

 tropous, oblong-lanceolate, short decurrent, acumen moderate, with some 

 teeth or sub-entire; costa very slender (33-48 //), sometimes simple to be- 

 yond the middle, more often bifurcate in stem leaves, more feeble and 

 shorter and sometimes almost wanting in branch leaves; median cells loose, 

 unequal as to length and breadth, basal almost equal, also a little broader, 



