102 American Midland Naturalist Monograph No. 6 



Key to t^e Species 



A. Autoicous: leaf -margins plane: seta 1.5 mm long or less; beak of operculum shorter 



than radius of capsule 1. A. lapponicum 



A. Dioicous: leaf-margins recurved below: seta about 3 mmi long; beak of operculum 



longer than radius of capsule 2. A. Mougeotii 



1. Amphidium lapponicum (Hedwig) Schimper 



(Anictangium lapponicum Hedwig; Z.ygodon lapponicus Bryologia Europaea) 



Densely cespitose, dark olive-green above, blackish below: stems dichoto- 

 mously branching, usually 1-3 cm high; leaves flexuous-spreading, lance-oblong 

 to lance-linear, 1.5-2.0 mm long, margins plane, acute, crisped when dry; costa 

 strong, ending below apex; basal cells large, thin-walled, pellucid to hyaline, 

 the upper small, quadrate-hexagonal, rather obscure, incrassate, papillose; peri- 

 chaetial leaves sheathing: seta very short, usually not over 1.5 mm; capsule 

 oval with distinct collum about as long as sporangium, partially immersed, 

 brownish, when dry constricted below mouth, urceolate, with 8 reddish striae, 

 the mouth forming a deep red, thickened rim; no peristome; lid red, lustrous, 

 small, low-conic, obliquely rostellate, the length of the beak not more than 

 one-half the diameter of the capsule; calyptra cucullate, small, reaching about 

 half-way down the urn, brownish; spores mature in early summer: autoicous, 

 the antheridial flowers axillary along the stem. 



In crevices of shaded rocks, rarely in calcareous habitats; Europe, Asia, 

 and, in North America, from Greenland to British Columbia south to northern 

 United States and to California. 



Rare in our region. Huntingdon Co.: Porter. (Porter's Catalogue). 



2. Amphidium Mougeotii (Bryologia Europaea) Schimper 

 {Z.ygodon Mougeotii Bryologia Europaea; Anoectangiitm Mougeotii Lindberg) 



Densely cespitose, in large tufts, yellowish-green above, rusty to blackish 

 below: stems usually 2-6 cm high, dichotomously branching; leaves spreading 

 or erect-spreading, crisped when dry, elongate lance-linear, acuminate, carinate, 

 margin narrowly revolute below, slightly irregular above; costa strong, vanish- 

 ing at apex; basal leaf-cells narrowly rectangular, rather thick-walled, above 

 shorter, sub-quadrate to rounded, incrassate, hardly papillose, pellucid; peri- 

 chaetial leaves sheathing only the base of seta: seta about 2-3 mm long; cap- 

 sule shortly exserted, narrowly oval with a distinct neck, when dry urceolate, 

 only slightly contracted belov/ mouth, 8-striate: peristome none; lid low, 

 obliquely rostrate, the length of the beak at least one-half the radius of the 

 capsule: calyptra cucullate; spores mature in summer or early autumn: dio- 

 icous: fruit rare. 



On damp, shaded, usually non-calcareous rocks, in mountains or hilly re- 

 gions; in Europe, Asia, and in North America, from Newfoundland to Alaska 

 south to Alabama and Oregon. To be looked for in the eastern part of 

 our range. 



