(367) 



Brxum pallcscois Schleich. Belt Mts. ; Little Prickly- 

 pear Canon ; Highwood Mts. ; Great Falls ; Columbia Falls, 

 July-Oct. (277, 178, 64). 



Brxum alpinum Huds. Head of Macdonald Lake, 5,000 

 ft., Aug. 3. Costa 140 mm. wide at base and often ending 

 1 cell below the apex in the upper leaves (335). 



Br yum Williamsi Philibert, Rev. Bryol. 28 : 31. 1900. 



(Plate 38.) 



Dioicous. In compact tufts felted with radicles below and 

 up to 3 cm. high. Stems somewhat branching, rather uni- 

 formly leaved above. Leaves erect, imbricated both wet and 

 drv. broadly ovate-lanceolate, entire or minutely serrulate at 

 apex, up to 2 mm. long, flat on borders or recurved along the 

 middle, with 2 or 3 rows of narrow, elongated cells form- 

 ing a distinct margin. Stout red costa, .080 mm. wide at 

 base, percurrent or ending 1 or 2 cells below apex. Leaf- 

 cells rather elongated rhomboidal to rectangular, median, 

 .050-. 060 mm. long and .016-. 018 mm. wide, all with 

 thickened but not pitted walls. Capsule elongated-pyri- 

 form, not contracted below the small mouth, up to 4 mm. 

 long, with distinct-collum equalling sporangium in length. 

 Lid rather low-convex mamillate. Annulus large. Teeth 

 somewhat papillose, with narrow border, the outer plates 

 below 2^-3^ times broader than high, inner lamellae up 

 to 30, parallel and not connected or irregular and joined by 

 very oblique cross-walls. Basilar membrane of endostome 

 extending about ]/ 2 up, the segments very narrow and papil- 

 lose, with narrow slits between articulations; cilia 2 or 3, 

 and short or nearly equalling segments in length and more 

 or less appendiculate. One or two rows of transversely 

 elongated cells about mouth of capsule. Seta up to 4 cm. 

 high. Nearly smooth spores up to .024 mm. 



Growing in very damp or wet crevices of rock by springs. 

 July 6, 1888, Missouri River bank below Great Falls. This 

 species is near Muhlenbeckii but differs in the very narrow 

 segments of endostome with narrow slits between the articu- 

 lations, not rounded perforations, the leaf-cells also are more 

 elongated above and less regularly short-rectangular below 



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