OF WESTERN PENNSYLVANIA 173 



Key to the Genera. 



a. Cilia well-developed: stem with a whorl of sub-floral shoots. 



3. Philonotis. 

 a. Cilia poorly developed or none. b. 



b. Leaf-cells matnillate or papillose; leaves S-seriate or pluriseri- 



ate. 2. Bartramia. 



h. Leaf-cells smooth; stem triangular and leaves 3-seriate. 



1. Plagiopus. 



1. PLAGIOPUS Bridel. 



Synoicous : quite slender, laxly to densely cespitose, dull 

 green, becoming brownish : stem erect or ascending, the outer 

 layer of cells lax, hyaline, the central strand poorly defined, 

 branching above the base, the shoots of about equal height; 

 leaves spreading to recurved, somewhat twisted but not cris- 

 pate when dry, from a non-sheathing base narrowly lanceolate, 

 acuminate, sharply carinate above, the margin usually revolute, 

 doubly serrate above; costa strong, percurrent, dorsally pro- 

 jecting and simply serrate upwards; leaf-cells incrassate, 

 smooth, the upper minute, shortly rectangular and quadrate, 

 hasally more elongate and pellucid, the alar slightly more lax 

 and quadrate: seta 1-1.5 cm. long, erect, castaneous, not 

 twisted when dry; capsule erect, somewhat inclined when dry, 

 globose, slightly arcuate, brown, finely striate, when dry some- 

 what shortened at the base and mouth, slightly curved and 

 strongly plicate; peristome double, the teeth smooth, narrow- 

 ly dagger-like, reddish-brown in the upper half, with inter- 

 lamellar thickenings, the inner peristome shorter and pale 

 yellow, cilia none ; lid small, short-conic ; spores mostly uni- 

 form, .024-.030 mm., warty. 



A genus of three species : one in New Zealand, one in Java, 

 and the following: 



1. Plagiopus oederi [Gunnerus] Limpricht. 

 (Bryum oederi Gunnerus ; Bartramia oederi Schwaegrichen ; 



Bartramia grandiflora Schwaegrichen). 



With characters essentially as given above for the genus. 

 The spores mature in spring. 



On moist soil and rocks in shady woods, mainly in non- 

 calcareous and hilly or mountainous districts; Europe, Asia, 

 and, in North America, from Canada to North Carolina and 

 west to the Rocky Mountains. It may eventually be found in 

 our region. 



2. BARTRAMIA Hedwig. 



Synoicous, paroicous, autoicous, or dioicous: slender to 

 robust, laxly to densely cespitose, the tufts often blue-green 

 .above, brownish-yellow inside : stem with central strand rarely 



