— 97 — 



Reprinted and abridged from the Bulletin of the Torrey Botanical Club, 30; Sept., 1903. 



REVISION OF THE NORTH AMERICAN SPECIES OF LESKEA. 



By Dr. G. N. Best. 



Key to the Species. 



EULESKEA : leaves papillose, costate; median cells usually isodiametric; peristomial 

 teeth abruptly incurved from a bulging base when dry. 

 Leaves ovate-lanceolate, acute to acuminate, more than twice as long as wide. 

 Leaves more or less secund; leaf-cells distinct. 



Capsules straight; operculum short-conic L.polycarpa. 

 Capsules curved; operculum long-conic. L. areiiicola. 



Leaves straight; leaf-cells small, indistinct; capsules straight, erect. 



L, 7)iicrocarpa. 



Leaves ovate, subacute to obtuse, less than twice as long as wide. 



Leaves symmetric, biplicate, margins often revolute. L. gi-acilescens. 



Leaves asymmetric, not plicate, margins plane. L. obscura. 



Heteroleskea: leaves smooth or nearly so, costate or ecostate, median cells longer than 

 wide; peristomial teeth erect when dry. 

 Leaves denticulate, ecostate. L. deiiticulata. 



Leaves entire or nearly so, costate; 

 Acumen longer than body; 



Costa subpercurrent, L. nervosa. 



Costa short. L. Williamsi. 



Acumen shorter shorter than body; 

 Costa short, bifld. 



Leaves smooi-h. L.tectoruin. 

 Leaves subpapillose. L. cyrtophylla. 



(1) Leskea polycarpa subobtusifolia (C. M. & K.) Best. 



Leskea subobtusifolia C. M, & K. ; Macoun, Cat. Can. PI. 6:169. 1892. 

 Subsp. L. obtusifolia Kiiidb. Eur. & N. Am. Bry. 25. 1896, 

 Tufts dirty yellowish green; stems and branches curved at tips: stem- 

 leaves subsecund, biplicate, ovate-oblong to ovate-lanceolate, subacute to 

 obtuse, obliquely pointed, the lower acuminate and blunt-pointed, i mm. 

 long, 0.4 mm. wide; leaf-cells as in L. polycarpa. Macoun, Canadian Musci 

 533- 



Professor Macoun has kindly loaned me the duplicate of the type, col" 

 lected at Sprout, Pass River, B. C, as well as other material from the same 

 locality and referred to it. All the specimens are destitute of fruit and are 

 unquestionably but forms of L. polycarpa, nearer however the var. paludosa 

 than the type. It is retained as a variety from the fact that the sporophyte 

 when found might possibly offer something distinctive entitling it to specific 

 rank. 



(2) Leskea arenicola Best. 



Plants somewhat rigid, in loosely spreading tufts, pale yellowish green 

 passing to reddish brown; stems 2-5 cm long, creeping, radiculose, pin- 

 nately branched; branches simple, ascending, sometimes curved; central 

 strand small, distinct: paraphyllia multiform, mostly linear-lanceolate : stem- 

 leaves rigid, secund, 0.4-0.5 mm. wide, 0.8-1 mm. long, ovate to ovate-lance- 

 olate, obliquely acuminate, acute to blunt-pointed, scarcely biplicate, margins 

 usually recurved at base, entire or sinuate-serrulate above, costa disappear- 

 ing in the acumen ; leaf-cells somewhat clear, stoutly uni-papillate on under 



