118 A MANUAL OF MOSSES 



g. Not very strongly contracted nor very decidedly plu-ate. 



h. 

 h. Stomata immersed; leaf-margins re volute. 



4. O. ohioense. 



h. Stomata not immersed; leaf-margins erect; leaves short and 

 broad, oblong-ovate. (Orthotrichum obtnsi- 



foliuin Schrader. 

 Schwaegrichen. ) 

 i. Capsule but little contracted below mouth when dry. ribs orange. 



segments 8; leaves oblong-lanceolate. 5. O. sdiunpcri. 



i. Capsule strongly contracted under the mouth when dn r . 



j- 



j. Capsule with very prominent reddish-brown ribs when dry, 

 half-emergent. 3. O. branuii. 



j. Capsule with less prominent light colored ribs, usually im- 

 mersed. (O. sordid mil Sullivant.) 



1. Orthotrichum strangulatum Schwaegrichen. 

 (O. porlcri Austin; O. cupulatum var. portcri Venturi). 



( Plate XIV ) 



Densely cespitose, about 1 cm. high : sterns densely leaved, 

 branched ; upper leaves lanceolate, about 3 mm. long, the lower 

 ovate, shorter, acute, margins entire or papillose, more or less 

 revolute, lamina often somewhat bi-stratose at margins and 

 apex ; costa strong, almost percurrent ; basal leaf-cells quadrate 

 at margin to rectangular (2:1) towards costa, smooth, hyaline, 

 the median rounded-hexagonal, dense, papillose, becoming to- 

 wards apex densely incrassate-rounded, arranged in quite regu- 

 lar rows: seta short, about 0.5 mm., capsule about 1.5 mm. 

 long, oblong-cylindric, tapering rather gradually to the seta, 

 when dry often only partly immersed, when wet always im- 

 mersed, dark reddish-brown, deeply 8-costate and 8-furrowed, 

 the cost?e with about 3 rows of rectangular cells with thicker 

 longitudinal walls, stomata few, immersed, calyptra mitrate. 

 quite densely erect-hirsute; operculum low with a rounded 

 apiculation ; peristome single, teeth paired, erect-spreading 

 when dry, irregularly triangular-lanceolate, about 8-articulate, 

 the divisural distinct and the teeth often split : the three or 

 four upper rows of cells of the capsule densely incrassate, 

 brown, pellucid like the costal and laterally oblong; spores 

 globose, papillose. .017-.020 mm., mature in summer. 



On rocks, Pennsylvania, Ohio, and Minnesota. 

 Cambria: : Cresson. James (Porter's Catalogue). 



Center : On limestone rocks, two miles west of 



Scotia, September 22, 1909. O. E. J. (Fig- 

 ured ). 



Westmoreland : Chestnut Ridge, above Hillside, on sand- 

 stone rocks. September 23, 1910. O. E. 

 J. and G. K. J. 



