224 Best : North American Pseudoleskea 



Key to Species 



Median cells of stem leaves usually not more than twice as long as wide. 



Leaves papillate on both surfaces. I. atrovirens 



Leaves smcoth or papillate on upper surface. 

 Leaves long-acuminate. 



2 . oligoclada 



Leaves acute to short- acuminate. 3. pallida. 



Median cells of stem leaves usually more than twice as long as wide. 



Stems long, branches few, without radicles. 4. denndata. 



Stems short, radiculose, freely branching. 



Capsule curved when dry, segments oblong-lanceolate. 5* fadicosa. 



Capsule straight when dry, segments narrowly linear. 



Basal cells oblong-quadrate in several rows 6. rigescens. 



Basal cells oblong-linear in two or three rows. 7. substriata. 



Eu-pseudoleskea : Plants rigid, papillose or smooth, median 

 leaf cells not more than twice as long as wide, capsule asym- 

 metric, endostomial band about % the length of the teeth. 



1. Pseudoleskea atrovirens (Dicks.) Bryol. Eur. 5 : 2. //. 4.7 j. 



1852 



Hypnum atrovirens Dickson fasc. 2. 10. 1790. 

 Leskea (?) patens Lindb. Soc. pro Fauna at Flora Fenn. 1880. 

 Pseudoleskea ticinensis Bott. Soc. Tosc. Sc. Nat. 1891. 

 Pseudoleskea atrovirens, var. patens (Lindb.) Hagen in Sched. 

 1894. 



Pseudoleskea heterocladioides Kindb. Rev. Bryol. 22: 83. 1895. 

 Pseudoleskea tenella Kindb. Eur. & N. Am. Bry. 50. 1896. 



In loosely spreading tufts, dark green above, reddish brown 

 below. Stems 3-5 cm. long, prostrate or prostrate-ascending, 

 radiculose, simple or divided, sparingly branched below, irregu- 

 larly pinnately above : branches simple, unequal, straight or 

 curved, paraphyllia linear-lanceolate : stem leaves asymmetric, ap- 

 pressed-incurved when dry, erect-spreading on all sides when 

 moist, the lower sometimes spreading-recurved, entire or serrate 

 above ; from an ovate or ovate-oblong subdecurrent base gradually 

 acute to somewhat abruptly acuminate, sharply and obliquely 

 pointed, straight or subsecund, margins recurved below, not rarely 

 also at the base of the acumen, lightly biplicate, costate to 

 .8-1.2 mm. long, .4— .55 mm. wide: cells of stem leaves nearly 

 isodiametric, incrassate, chlorophyllose, unipapillate on both sur- 

 faces, papillae central, conic on upper surface, round and flat on 

 lower : median cells quadrate-hexagonal, rarely suborbicular or 

 oblong-hexagonal, .007-.009 mm. wide ; also the basal quadrate, 

 in several rows ; apical oval-oblong. Dioicous : inner perichetial 



